2014阿里巴巴WEB前端实习生在线笔试题
2014-05-30 07:50
459 查看
2014年3月31日晚，我怀着略微忐忑的心情（第一次在线笔试^_^!!）进行了笔试，阿里巴巴的笔试题共有10道，几乎包含了Web前端开发的各个方面，有程序题、有叙述题，时间非常紧张，只完成了大概6道题。下面把遇到的题目跟大家分享一下！
1、
问：为什么以上两个<p> 标签中的文字颜色都是橙色的？
这里涉及到了CSS中的层叠和特殊性问题，首先按照上下顺序，第一个<p>元素它的样式很明显是由div.outer p 定义的，所以是橙色。第二个<p>元素的样式是由样式表中的两个样式同时定义，而且同样是color样式。根据《CSS权威指南》中的介绍，当CSS样式发生层叠时，要通过层叠规则来安排最终元素匹配的样式。
CSS2.1的层叠规则中的规定，在没有!important标志时，要按照特殊性排序，如果还不能比较完，就后面覆盖前面。
可以参考：CSS层叠规则
2、请实现一个Event类，继承自此类的对象都会拥有两个方法on和trigger，类声明如下，请写出完整代码：
[javascript] view
plaincopy
function Event() {}
Event.prototype.on = function(eventName, callback) {
//注册事件监听
}
Event.prototype.trigger = function(eventName, data) {
//触发事件
}
要求实现一个多行文本输入框，固定宽度。可根据用户输入的内容多少进行高度自适应变化。如，用户输入了1行文字，则输入框显示为1行，而有2行文字，就显示2行。如微博的评论回复。
[javascript] view
plaincopy
<!DOCTYPE html>
<html>
<head>
<title>文本框换行</title>
<meta charset="utf-8">
<style>
.txt {
border: 1px solid #CCC;
width: 200px;
padding: 3px;
font: 12px/16px Simsun;
outline: none;
resize: none;
word-wrap: break-word;
word-break: break-all;
overflow: hidden;
}
</style>
<script>
window.addEventListener('load', function () {
(function (o, e, t) {
//创建一个pre标签，用来计算文字应有高度
e = document.createElement("pre");
//给pre添加上和文本域一样的样式
e.className = "txt";
//设置绝对定位到屏幕外来隐藏它
e.style.position = "absolute";
e.style.left = "-9999px";
//创建一个文本节点来操作，避免直接操作HTML
e.appendChild(t = document.createTextNode(""));
//给pre的末尾添加一个换行，因为pre会吞掉末尾的一个换行
e.appendChild(document.createTextNode("\n"));
//把pre放入文档中
document.body.appendChild(e);
//文本域键盘事件时计算高度
o.onkeydown = o.onkeyup = function () {
//IE8下\r\n在PRE标签中会被解析为两行，所以需要一个替换
//如果觉得这样会影响效率可以先判断浏览器
t.data = o.value.replace(/\r\n/g, "\n");
o.style.height = e.offsetHeight - 8 + "px";
};
//初始时计算一次
o.onkeydown();
//为了避免换行时闪的太厉害，稍微阻止下滚动
o.onscroll = function () {
o.scrollTop = 0
};
})(document.getElementById("o"));
}, false);
</script>
</head>
<body>
<textarea id="o" class="txt">来呀，来编辑我呀～</textarea>
</body>
</html>
来自网络：http://www.web-tinker.com/article/20151.html
4、
编写一个JavasSript函数，给定一个DOM节点node和一个正整数n,返回node的所有第n代后代节点（直接子节点为第1代）
[javascript] view
plaincopy
function getDescendants(node, n) {
// return an Array
}
[javascript] view
plaincopy
<script type="text/javascript" >
function getDescendants(node, n) {
//node, n
var childArr = [];
var len,tempArr,childNodelist;
childArr.push(node);
for(var i = 0; i<n ; i++){
len = childArr.length;
tempArr = [];
for(var j = 0;j<len;j++){
childNodeList = makeArray(childArr[j].childNodes);
tempArr = tempArr.concat(childNodeList);
}
childArr = tempArr;
}
return childArr;
}
var makeArray = function(obj){
return Array.prototype.slice.call(obj,0);
}
var result = getDescendants(document.getElementById("content"),2);
alert(result);
</script>
5、有2个int型已经去重的数组a和b，都是已经从小到大排序好的。要求遍历b数组的数字，如果这个数字出现在a中，就将其从a删去；反之将其插入到a的适当位置，使a保持排序状态。
[javascript] view
plaincopy
<script type="text/javascript" charset="utf-8">
//有2个int型已经去重的数组a和b，都是已经从小到大排序好的。要求遍历b数组的数字，
//如果这个数字出现在a中，就将其从a删去；反之将其插入到a的适当位置，使a保持排序状态。
var mySort = {};
mySort.sortArr = function(a, b) {
var pos = 0;
for (var i = 0; i < b.length; i++) {
pos = mySort.checkRepeat(a, b[i],pos);
}
}
mySort.checkRepeat = function(a, v, pos) {
var isChanged = false;
if (a != null && a != undefined && a.length > 0) {
for (var j = pos; j < a.length; j++) {
if (a[j] == v) {
a.splice(j, 1);
break;
} else if (a[j] > v) {
a.splice(j, 0, v);
break;
}
}
if(j == a.length){
a.push(v);
}
return j;
}
}
var a = [2,7,12,25,36,64];
var b = [2,3,9,32,36,56,87];
document.write("合并前数组a为："+a.toString()+"<br>");
document.write("合并前数组b为："+b.toString()+"<br>");
mySort.sortArr(a,b);
document.write("合并后数组a为："+a.toString());
//结果是:
合并前数组a为：2,7,12,25,36,64
合并前数组b为：2,3,9,32,36,56,87
合并后数组a为：3,7,9,12,25,32,56,64,87
6、请描述一下从用户输入网址开始，到网页最后呈现出来的全过程，越详细越好，包括各种事件等。
7、
8、请评价以下代码并给出改进意见。
参考答案：(网友提供)
a) 功能：事件注册
b) 优点：跨浏览器，特性探测，性能优化。缺点：document.all
c) 作用：使得IE中listener的this 为 el，与其它浏览器一致
d) 改进：document.all改成window.attachEvent; useCapture的默认值
9、你最近看的前端相关技术书是什么？常关注的博客是哪些？你觉着哪个网站的交互做的好，为什么？
《JavaScript权威指南》、《JavaScript语言精粹》
W3cfuns、阮一峰、前端前沿、WebHek、前端开发，等等
当时就写了淘宝的交互，从购物车、商品分类、响应式设计等方面讲了一下。
10、阅读如下代码：
问：1、为什么最终小狗叫了200声汪？请详细说明为什么。2、修改代码setTimeout部分代码，实现每隔1秒调用i（从1到10递增）次dog()。
1、第一题重点在于函数作用域的问题。
2、 修改后的setTimeout函数是
[javascript] view
plaincopy
for (var i = 0; i < 10; i++) {
(function(a) {
setTimeout(function() {
for (var j = 1; j <= a; j++) {
document.write(dog()+" "+a+"<br>");
}
1、
<div class="dp-highlighter bg_html" style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; background-color: rgb(231, 229, 220); width: 936.53125px; overflow: auto; padding-top: 1px; margin: 18px 0px !important;"><div class="bar" style="padding-left: 45px;"><div class="tools" style="padding: 3px 8px 10px 10px; font-size: 9px; line-height: normal; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; background-color: rgb(248, 248, 248); border-left-width: 3px; border-left-style: solid; border-left-color: rgb(108, 226, 108);"><strong>[html]</strong> <a target=_blank href="http://blog.csdn.net/javascriptcoder/article/details/22910827#" class="ViewSource" title="view plain" style="color: rgb(160, 160, 160); text-decoration: none; background-image: url(http://static.blog.csdn.net/scripts/SyntaxHighlighter/styles/images/default/ico_plain.gif); background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;">view plain</a><a target=_blank href="http://blog.csdn.net/javascriptcoder/article/details/22910827#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; background-image: url(http://static.blog.csdn.net/scripts/SyntaxHighlighter/styles/images/default/ico_copy.gif); background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;">copy</a><a target=_blank href="https://code.csdn.net/snippets/274217" target="_blank" title="在CODE上查看代码片" style="color: rgb(160, 160, 160); text-decoration: none; background-image: none; background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;"><img src="https://code.csdn.net/assets/CODE_ico.png" width="12" height="12" alt="在CODE上查看代码片" style="border: none; max-width: 100%; position: relative; top: 1px; left: 2px;" /></a><a target=_blank href="https://code.csdn.net/snippets/274217/fork" target="_blank" title="派生到我的代码片" style="color: rgb(160, 160, 160); text-decoration: none; background-image: none; background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;"><img src="https://code.csdn.net/assets/ico_fork.svg" width="12" height="12" alt="派生到我的代码片" style="border: none; max-width: 100%; position: relative; top: 2px; left: 2px;" /></a><div style="position: absolute; left: 438px; top: 546px; width: 18px; height: 18px; z-index: 99;"></div></div></div><ol start="1" class="dp-xml" style="padding: 0px; border: none; list-style-position: initial; list-style-image: initial; background-color: rgb(255, 255, 255); color: rgb(92, 92, 92); margin: 0px 0px 1px 45px !important;"><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"><!doctype html</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">html</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">head</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">style</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="attribute" style="margin: 0px; padding: 0px; border: none; color: red; background-color: inherit;">type</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">=</span><span class="attribute-value" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">"text/css"</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> div:not(.outer) p { color: purple; } </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> div.outer p { color: orange; } </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">style</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">head</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">body</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">div</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="attribute" style="margin: 0px; padding: 0px; border: none; color: red; background-color: inherit;">class</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">=</span><span class="attribute-value" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">"outer"</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">p</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> 我是 outer 里面的字 </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">p</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">div</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="attribute" style="margin: 0px; padding: 0px; border: none; color: red; background-color: inherit;">class</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">=</span><span class="attribute-value" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">"inner"</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"><</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">p</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> 我是 inner 里面的字 </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">p</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">div</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">div</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">body</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;"></</span><span class="tag-name" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">html</span><span class="tag" style="margin: 0px; padding: 0px; border: none; color: rgb(153, 51, 0); background-color: inherit; font-weight: bold;">></span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span></span></li></ol></div>问：为什么以上两个<p> 标签中的文字颜色都是橙色的？
这里涉及到了CSS中的层叠和特殊性问题，首先按照上下顺序，第一个<p>元素它的样式很明显是由div.outer p 定义的，所以是橙色。第二个<p>元素的样式是由样式表中的两个样式同时定义，而且同样是color样式。根据《CSS权威指南》中的介绍，当CSS样式发生层叠时，要通过层叠规则来安排最终元素匹配的样式。
CSS2.1的层叠规则中的规定，在没有!important标志时，要按照特殊性排序，如果还不能比较完，就后面覆盖前面。
可以参考：CSS层叠规则
2、请实现一个Event类，继承自此类的对象都会拥有两个方法on和trigger，类声明如下，请写出完整代码：
[javascript] view
plaincopy
function Event() {}
Event.prototype.on = function(eventName, callback) {
//注册事件监听
}
Event.prototype.trigger = function(eventName, data) {
//触发事件
}
<span style="font-family: Arial, Helvetica, sans-serif;">参考:<a target=_blank target="_blank" href="http://html5ify.com/eventproxy/eventproxy.html" style="color: rgb(255, 153, 0); text-decoration: none;">http://html5ify.com/eventproxy/eventproxy.html</a> </span>
<span style="font-family: Arial, Helvetica, sans-serif;">3、</span>
要求实现一个多行文本输入框，固定宽度。可根据用户输入的内容多少进行高度自适应变化。如，用户输入了1行文字，则输入框显示为1行，而有2行文字，就显示2行。如微博的评论回复。
[javascript] view
plaincopy
<!DOCTYPE html>
<html>
<head>
<title>文本框换行</title>
<meta charset="utf-8">
<style>
.txt {
border: 1px solid #CCC;
width: 200px;
padding: 3px;
font: 12px/16px Simsun;
outline: none;
resize: none;
word-wrap: break-word;
word-break: break-all;
overflow: hidden;
}
</style>
<script>
window.addEventListener('load', function () {
(function (o, e, t) {
//创建一个pre标签，用来计算文字应有高度
e = document.createElement("pre");
//给pre添加上和文本域一样的样式
e.className = "txt";
//设置绝对定位到屏幕外来隐藏它
e.style.position = "absolute";
e.style.left = "-9999px";
//创建一个文本节点来操作，避免直接操作HTML
e.appendChild(t = document.createTextNode(""));
//给pre的末尾添加一个换行，因为pre会吞掉末尾的一个换行
e.appendChild(document.createTextNode("\n"));
//把pre放入文档中
document.body.appendChild(e);
//文本域键盘事件时计算高度
o.onkeydown = o.onkeyup = function () {
//IE8下\r\n在PRE标签中会被解析为两行，所以需要一个替换
//如果觉得这样会影响效率可以先判断浏览器
t.data = o.value.replace(/\r\n/g, "\n");
o.style.height = e.offsetHeight - 8 + "px";
};
//初始时计算一次
o.onkeydown();
//为了避免换行时闪的太厉害，稍微阻止下滚动
o.onscroll = function () {
o.scrollTop = 0
};
})(document.getElementById("o"));
}, false);
</script>
</head>
<body>
<textarea id="o" class="txt">来呀，来编辑我呀～</textarea>
</body>
</html>
来自网络：http://www.web-tinker.com/article/20151.html
4、
编写一个JavasSript函数，给定一个DOM节点node和一个正整数n,返回node的所有第n代后代节点（直接子节点为第1代）
[javascript] view
plaincopy
function getDescendants(node, n) {
// return an Array
}
[javascript] view
plaincopy
<script type="text/javascript" >
function getDescendants(node, n) {
//node, n
var childArr = [];
var len,tempArr,childNodelist;
childArr.push(node);
for(var i = 0; i<n ; i++){
len = childArr.length;
tempArr = [];
for(var j = 0;j<len;j++){
childNodeList = makeArray(childArr[j].childNodes);
tempArr = tempArr.concat(childNodeList);
}
childArr = tempArr;
}
return childArr;
}
var makeArray = function(obj){
return Array.prototype.slice.call(obj,0);
}
var result = getDescendants(document.getElementById("content"),2);
alert(result);
</script>
5、有2个int型已经去重的数组a和b，都是已经从小到大排序好的。要求遍历b数组的数字，如果这个数字出现在a中，就将其从a删去；反之将其插入到a的适当位置，使a保持排序状态。
[javascript] view
plaincopy
<script type="text/javascript" charset="utf-8">
//有2个int型已经去重的数组a和b，都是已经从小到大排序好的。要求遍历b数组的数字，
//如果这个数字出现在a中，就将其从a删去；反之将其插入到a的适当位置，使a保持排序状态。
var mySort = {};
mySort.sortArr = function(a, b) {
var pos = 0;
for (var i = 0; i < b.length; i++) {
pos = mySort.checkRepeat(a, b[i],pos);
}
}
mySort.checkRepeat = function(a, v, pos) {
var isChanged = false;
if (a != null && a != undefined && a.length > 0) {
for (var j = pos; j < a.length; j++) {
if (a[j] == v) {
a.splice(j, 1);
break;
} else if (a[j] > v) {
a.splice(j, 0, v);
break;
}
}
if(j == a.length){
a.push(v);
}
return j;
}
}
var a = [2,7,12,25,36,64];
var b = [2,3,9,32,36,56,87];
document.write("合并前数组a为："+a.toString()+"<br>");
document.write("合并前数组b为："+b.toString()+"<br>");
mySort.sortArr(a,b);
document.write("合并后数组a为："+a.toString());
//结果是:
合并前数组a为：2,7,12,25,36,64
合并前数组b为：2,3,9,32,36,56,87
合并后数组a为：3,7,9,12,25,32,56,64,87
6、请描述一下从用户输入网址开始，到网页最后呈现出来的全过程，越详细越好，包括各种事件等。
7、
8、请评价以下代码并给出改进意见。
<div class="dp-highlighter bg_javascript" style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; background-color: rgb(231, 229, 220); width: 936.53125px; overflow: auto; padding-top: 1px; margin: 18px 0px !important;"><div class="bar" style="padding-left: 45px;"><div class="tools" style="padding: 3px 8px 10px 10px; font-size: 9px; line-height: normal; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; background-color: rgb(248, 248, 248); border-left-width: 3px; border-left-style: solid; border-left-color: rgb(108, 226, 108);"><strong>[javascript]</strong> <a target=_blank href="http://blog.csdn.net/javascriptcoder/article/details/22910827#" class="ViewSource" title="view plain" style="color: rgb(160, 160, 160); text-decoration: none; background-image: url(http://static.blog.csdn.net/scripts/SyntaxHighlighter/styles/images/default/ico_plain.gif); background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;">view plain</a><a target=_blank href="http://blog.csdn.net/javascriptcoder/article/details/22910827#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; background-image: url(http://static.blog.csdn.net/scripts/SyntaxHighlighter/styles/images/default/ico_copy.gif); background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;">copy</a><a target=_blank href="https://code.csdn.net/snippets/274217" target="_blank" title="在CODE上查看代码片" style="color: rgb(160, 160, 160); text-decoration: none; background-image: none; background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;"><img src="https://code.csdn.net/assets/CODE_ico.png" width="12" height="12" alt="在CODE上查看代码片" style="border: none; max-width: 100%; position: relative; top: 1px; left: 2px;" /></a><a target=_blank href="https://code.csdn.net/snippets/274217/fork" target="_blank" title="派生到我的代码片" style="color: rgb(160, 160, 160); text-decoration: none; background-image: none; background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;"><img src="https://code.csdn.net/assets/ico_fork.svg" width="12" height="12" alt="派生到我的代码片" style="border: none; max-width: 100%; position: relative; top: 2px; left: 2px;" /></a><div style="position: absolute; left: 475px; top: 4970px; width: 18px; height: 18px; z-index: 99;"></div></div></div><ol start="1" class="dp-c" style="padding: 0px; border: none; list-style-position: initial; list-style-image: initial; background-color: rgb(255, 255, 255); color: rgb(92, 92, 92); margin: 0px 0px 1px 45px !important;"><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">if</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> (window.addEventListener) { </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">var</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> addListener = </span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> (el, type, listener, useCapture) { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> el.addEventListener(type, listener, useCapture); </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> }; </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">} <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">else</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">if</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> (document.all) { </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> addListener = <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> (el, type, listener) { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> el.attachEvent(<span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">"on"</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> + type, </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> () { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> listener.apply(el); </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> }); </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> }; </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">} </span></li></ol></div>参考答案：(网友提供)
a) 功能：事件注册
b) 优点：跨浏览器，特性探测，性能优化。缺点：document.all
c) 作用：使得IE中listener的this 为 el，与其它浏览器一致
d) 改进：document.all改成window.attachEvent; useCapture的默认值
9、你最近看的前端相关技术书是什么？常关注的博客是哪些？你觉着哪个网站的交互做的好，为什么？
《JavaScript权威指南》、《JavaScript语言精粹》
W3cfuns、阮一峰、前端前沿、WebHek、前端开发，等等
当时就写了淘宝的交互，从购物车、商品分类、响应式设计等方面讲了一下。
10、阅读如下代码：
<div class="dp-highlighter bg_javascript" style="font-family: Consolas, 'Courier New', Courier, mono, serif; font-size: 12px; background-color: rgb(231, 229, 220); width: 936.53125px; overflow: auto; padding-top: 1px; margin: 18px 0px !important;"><div class="bar" style="padding-left: 45px;"><div class="tools" style="padding: 3px 8px 10px 10px; font-size: 9px; line-height: normal; font-family: Verdana, Geneva, Arial, Helvetica, sans-serif; color: silver; background-color: rgb(248, 248, 248); border-left-width: 3px; border-left-style: solid; border-left-color: rgb(108, 226, 108);"><strong>[javascript]</strong> <a target=_blank href="http://blog.csdn.net/javascriptcoder/article/details/22910827#" class="ViewSource" title="view plain" style="color: rgb(160, 160, 160); text-decoration: none; background-image: url(http://static.blog.csdn.net/scripts/SyntaxHighlighter/styles/images/default/ico_plain.gif); background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;">view plain</a><a target=_blank href="http://blog.csdn.net/javascriptcoder/article/details/22910827#" class="CopyToClipboard" title="copy" style="color: rgb(160, 160, 160); text-decoration: none; background-image: url(http://static.blog.csdn.net/scripts/SyntaxHighlighter/styles/images/default/ico_copy.gif); background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; text-indent: -2000px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;">copy</a><a target=_blank href="https://code.csdn.net/snippets/274217" target="_blank" title="在CODE上查看代码片" style="color: rgb(160, 160, 160); text-decoration: none; background-image: none; background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;"><img src="https://code.csdn.net/assets/CODE_ico.png" width="12" height="12" alt="在CODE上查看代码片" style="border: none; max-width: 100%; position: relative; top: 1px; left: 2px;" /></a><a target=_blank href="https://code.csdn.net/snippets/274217/fork" target="_blank" title="派生到我的代码片" style="color: rgb(160, 160, 160); text-decoration: none; background-image: none; background-color: inherit; border: none; padding: 1px; margin: 0px 10px 0px 0px; font-size: 9px; display: inline-block; width: 16px; height: 16px; background-position: 0% 0%; background-repeat: no-repeat no-repeat;"><img src="https://code.csdn.net/assets/ico_fork.svg" width="12" height="12" alt="派生到我的代码片" style="border: none; max-width: 100%; position: relative; top: 2px; left: 2px;" /></a><div style="position: absolute; left: 475px; top: 5515px; width: 18px; height: 18px; z-index: 99;"></div></div></div><ol start="1" class="dp-c" style="padding: 0px; border: none; list-style-position: initial; list-style-image: initial; background-color: rgb(255, 255, 255); color: rgb(92, 92, 92); margin: 0px 0px 1px 45px !important;"><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">var</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> dog = </span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> () { </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">return</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'汪'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">; </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">}; </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">var</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> cat = </span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> () { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">return</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'喵'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">; </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">}; </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">(<span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> () { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">if</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> (cat() === </span><span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'喵喵'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">) { </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> dog = <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> () { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">return</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'汪汪'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">; </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> } </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> } </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> cat() { </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">return</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> </span><span class="string" style="margin: 0px; padding: 0px; border: none; color: blue; background-color: inherit;">'喵喵'</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;">; </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> } </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">})(); </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">for</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> (</span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">var</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> i = 0; i < 10; i++) { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> setTimeout(<span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">function</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> () { </span></span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> <span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">for</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> (</span><span class="keyword" style="margin: 0px; padding: 0px; border: none; color: rgb(0, 102, 153); background-color: inherit; font-weight: bold;">var</span><span style="margin: 0px; padding: 0px; border: none; background-color: inherit;"> j = 1; j <= i; j++) { </span></span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> console.log(dog()); </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> } </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> }, </span></li><li style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; background-color: rgb(248, 248, 248); line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;"> 1000 * i); </span></li><li class="alt" style="border-style: none none none solid; border-left-width: 3px; border-left-color: rgb(108, 226, 108); list-style: decimal-leading-zero outside; color: inherit; line-height: 18px; margin: 0px !important; padding: 0px 3px 0px 10px !important;"><span style="margin: 0px; padding: 0px; border: none; color: black; background-color: inherit;">} </span></li></ol></div>问：1、为什么最终小狗叫了200声汪？请详细说明为什么。2、修改代码setTimeout部分代码，实现每隔1秒调用i（从1到10递增）次dog()。
1、第一题重点在于函数作用域的问题。
2、 修改后的setTimeout函数是
[javascript] view
plaincopy
for (var i = 0; i < 10; i++) {
(function(a) {
setTimeout(function() {
for (var j = 1; j <= a; j++) {
document.write(dog()+" "+a+"<br>");
}
内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理 
相关文章推荐
- 2014阿里巴巴WEB前端实习生在线笔试题
- 2014阿里巴巴WEB前端实习生在线笔试题
- 2014阿里巴巴WEB前端实习生在线笔试题
- 阿里巴巴2014实习生前端招聘在线笔试题
- 2015阿里巴巴前端实习生在线笔试题
- 2015阿里巴巴前端实习生在线笔试考后总结
- 2014阿里巴巴web前端实习生试题分析（1）
- 2014阿里巴巴前端在线笔试题及自己所做解答
- 2015阿里巴巴前端实习生在线笔试题
- 2015阿里巴巴前端实习生在线笔试题
- 阿里巴巴2015校园招聘前端在线笔试题
- 阿里巴巴2014实习生招聘笔试题
- 2015阿里巴巴秋季校园招聘前端在线笔试题个人参考答案--第二波
- 阿里巴巴2014实习生笔试题-研发工程师-北京站
- 记2012年百度web前端研发实习生的笔试面试经历
- 阿里巴巴2015秋季校园招聘前端开发工程师在线笔试题及答案
- 2014阿里巴巴实习生招聘-研发工程师笔试题/网络编程小结
- 2014阿里巴巴前端开发工程师暑期实习在线测试题目及答案思路
- 2011年腾讯实习生应聘（软件开发>Web前端>flash方向）笔试面试经历
- 2014阿里巴巴实习生笔试题目