1.创建对象
1.1 字面量创建方法
1 var box={ 2 name:'小明', 3 age:20, 4 qq:23435235, 5 }; 6 alert(box.qq) 7 alert(box['age'])
1.2 new创建
var box=new Object() box.name='小明'; box.age=20; box.qq=123421545; alert(box.name) alert(box['age'])
2.对象中属性的操作
2.1 查询属性
var box=new Object() box.name='小明'; box.age=20; box.qq=123421545; box.qq //得到属性qq box.age //得到属性age
2.2 设置属性
var box={ name:'小明', age:20, qq:24253241, }; box.qq=4641451; //变更qq属性值 box.wechat='学海无涯';//创建一个新的属性并且赋值
2.3 删除属性
var box={ name:'小明', age:20, qq:24253241, }; delete box.name //删除属性name delete box.age //删除属性age
2.4 检测属性(判断某个属性是否存在于某个对象中)
2.4.1 in运算符检测
var box={ name:'小明', age:20, qq:24253241, }; alert('name' in box)//true alert(name in box) //false
2.4.2 hasOwnProperty检测
var box={ name:'小明', age:20, qq:24253241, }; alert(box.hasOwnProperty('name'))//true alert(box.hasOwnProperty(name)) //false
2.4.3!== undefined检测
var box={ name:'小明', age:20, qq:24253241, }; alert(box.name!==undefined) //true alert(box.weixin!==undefined) //false
2.5 枚举属性(遍历对象的各个属性)