数组多功能splice()方法的插入，删除，替换

多功能splice()插入、删除、替换

<script type="text/javascript">
var arr=['A','B','C','D','E','F','G'];
arr.splice(3,2,'苹果','葡萄');  //替换一些项
console.log(arr);
</script>

<script type="text/javascript">
// 更改一些项
var arr=['A','B','c','d','e','f','g']
arr.splice(3,2,'x','y','x','斯密码'); //更改一些项
console.log(arr);

</script>

<script type="text/javascript">
var arr=['a','b','c','d','e','f','g']
arr.splice(2,1,'哈哈');//更改一个项
console.log(arr);
</script>

<script type="text/javascript">
var arr=['a','b','c','d','e','f','g'];
arr.splice(2,4) //没有东西可以替换，就直接删除
console.log(arr);

</script>

<script type="text/javascript">
var arr=['a','b','c','d','e','f','g'];
arr.splice(2);
console.log(arr);
</script>

<script type="text/javascript">
var arr=['a','b','c','d','e','f','g'];
arr.splice(2,0,'嘻嘻','哈哈'); //插入一些项
console.log(arr);
</script>

<script type="text/javascript">
//删除数组最后五项
var arr['a','b','c','d','e','f','g'];
arr.pop();
arr.pop();
arr.pop();
arr.pop();
arr.pop();
//简化为
for(var i=0; i<arr.length; i++;){
arr[i].pop();
}
//也可以
arr.splice(-5);
console.log(arr);
</script>