javascript的函数和对象

//定义无参函数
function myFunc(){
document.writeln("this is a statement");
}
myFunc();

//定义有参函数
function myFunc2(name,weather){
document.writeln("hello "+name+".");
document.writeln("It is "+weather+" today");
}
myFunc2("jason","sunny");

//定义会返回结果的函数
function myFunc3(name){
return ("Hello"+name+".");
}
document.writeln(myFunc3("jason"));

//原始方法
var myData=new Object();
myData.name="jason";
myData.weather="sunny";
document.writeln("hello "+myData.name+" Toady is "+myData.weather+".");

//使用对象字面量
var myData2={
name:"keven",weather:"rainy"
};
document.writeln("hello "+myData2.name+" Toady is "+myData2.weather+".");

//将函数用作方法
var myData3={
name:"benny",
weather:"cloudy",
printMessages:function(){
document.writeln("hello "+this.name+" Toady is "+this.weather+".");
}
};
myData3.printMessages();

//读取和修改对象属性值
var myData4={
name:"jane",
weather:"summer"
};
myData4.name="joe";
myData4["weather"]="warm";
document.writeln("hello "+myData4.name+" Toady is "+myData4["weather"]+".");

//枚举对象属性值
var myData5={
name:"angel",
weather:"sunny",
printMessages:function(){
document.writeln("hello "+this.name+" Toady is "+this.weather+".");
}
};
for(var prop in myData5){
document.writeln("Name:"+prop+" Value:"+myData5[prop]);
}

//为对象添加新属性
var myData6={
name:"sam",
weather:"spring"
};
myData6.dayOfWeek="Monday";
//为对象添加新方法
myData6.sayHello=function(){
document.writeln("hello");
}
//删除对象的属性
delete myData6.name;
delete myData6.sayHello;

//判断对象是否具有某个属性
var myData7={
name:"john",
weather:"sunny"
};
var hasName="name" in myData7;
var hasDate="date" in myData7;
document.writeln("HasName: "+hasName);
document.writeln("HasDate: "+hasDate);