1 删除一个对象的key值
2 方法1：
3 var data={
4 province:'',
5 city:''
6 }
7 delete(data["province"]);
8 console.log(data)//data={city:''}
9 方法2：
10 var data={
11 province:'',
12 city:''
13 }
14 delete data.province
15 console.log(data)//data={city:''}
1 判断对象是否存在
2 1、JSON.stringify(要判断的对象)==="{}" h5
3 2、Object.keys(要判断的对象).length===0 h5 ES6的新方法
4 3、var keys=[]
5 for(var key in {要判断的对象}){
6 keys.push(key)
7 }
8 keys = =[] ??
9 var keys=[]
10 for(var key in {a:1,d:2}){
11 keys.push(key)
12 }
13 keys = =["a","b"]
14 4、jquery的isEmptyObject方法
15 var data = {}
16 var b = $.isEmptyObject(data);
17 alert(b);//true
18 5、Object.getOwnPropertyNames()方法
19 var data ={};
20 var arr = Object.getOwnPropertyNames(data);
21 alert(arr.length==0);//true 不兼容IE8
