JavaScript创建对象的两种方法和遍历对象的属性
创建新对象有两种不同的方法:
- 定义并创建对象的实例
- 使用函数来定义对象,然后创建新的对象实例
1.定义并创建对象的实例
var person=new Object(); person.firstname="John"; person.lastname="Doe"; person.age=50; person.eyecolor="blue";
或者
var person={firstname:"John",lastname:"Doe",age:50,eyecolor:"blue"}
2.使用函数来定义对象,然后创建新的对象实例
function person(firstname,lastname,age,eyecolor){ this.firstname=firstname; this.lastname=lastname; this.age=age; this.eyecolor=eyecolor; } var myFather=new person("John","Doe",50,"blue");
myFather.hobby = "pingpang";//添加属性
把方法添加到 JavaScript 对象
function person(firstname,lastname,age,eyecolor){ this.firstname=firstname; this.lastname=lastname; this.age=age; this.eyecolor=eyecolor; this.changeName=changeName; function changeName(name){ this.lastname=name; } } myMother=new person("Sally","Rally",48,"green"); myMother.changeName("Doe"); document.write(myMother.lastname);//输出Doe
遍历JavaScript对象的属性
function myFunction(){ var x; var txt=""; var person={fname:"Bill",lname:"Gates",age:56}; for (x in person){ txt=txt + person[x]; } document.getElementById("demo").innerHTML=txt; }