创建javaScript 对象

创建新实例person 并向其添加四个属性：

person=new Object();
person.firstname="Bill";
person.lastname="Gates";
person.age=56;
person.eyecolor="blue";

person{firstname:"john",lastname:"doe",age:50,eyecolor:"blue"};

function person(firstname,lastname,age,eyecolor){
this.first=firstname;
this.lastname=lastname;
this.age=age;
this.eyecolor=eyecol

创建JavaScript对象后就可以利用对象创建实例：

var myFather = new person("Bill","Gates",56,"blue");
var myMother=new person("Steve","Jobs",48,"green");

 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;
}
}

javaScript  类

  javaScript类是面向对象的语言，但javaScript不使用类

 在javaScript 中，不会创建类，也不会通过类来创建对象

javaScript基于prototype（原型） 而不是基于类的

javaScript  for..in循环

 for...in会遍历对象中的每个属性

var person=={fname:"bill",lname:"gates",age"56};

for(x in person)
{
txt=txt+person[x];
}
document.getElementById("demo").innerHTML=txt;

将会输出：

billgates56