JavaScript对象属性

var person={
username:'king',
age:12,
salary:123,
addr:'shanghai'
sex:'nan'
};

//查询属性

console.log(person.username);
//如果属性不确定需要用[]
var key='username';
console.log(person.key); //undefined
console.log(person[key]); //king
console.log(person['key']);  //undefined
function PersonInfo(name,age,sex){
this.name=name;
this.age=age;
this.sex=sex;
//当处于某对象方法内部的时候，可以通过this来访问同一对象的属性
}
var person1=new PersonInfo('king',34,'nan');
console.log(person1.name);

//添加属性

var obj={};//空对象
obj.username='king';
obj.age=23;
obj['test']='hahha haha';

//修改指定属性

obj.username='xiaohong';

//删除属性

delete obj.test;

//for in 遍历属性

var obj1={
x:1,
y:2
};
for(var p in obj1){
console.log(p+'\n');
}

//对象中有方法

var obj2={
username:'qw',
sayHi:function(){
 return 'haha';
}
};