創建新對象有兩種不同的方法：

• 定義並創建對象的實例
• 使用函數來定義對象，然後創建新的對象實例

1.定義並創建對象的實例

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.使用函數來定義對象，然後創建新的對象實例

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";//添加屬性

把方法添加到 JavaScript 對象

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);//輸出Doe

遍歷JavaScript對象的屬性

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;
}

JavaScript創建對象的兩種方法和遍歷對象的屬性