js, 对已有对象,添加新属性值

var it={ name: 'yoyo' , }
 console.log(it)
 it["device"] = { id: 123 }
 it["serverType"] = "1";
 it['arr']=[]
 console.log(it)

var obj = {}; //或者 var obj=new Object();
var key = "name";
var value = "张三丰"
obj[key] = value;
console.log(obj)

var a =[{name: 'Tom',age:20},{name: 'Tom2',age:22}]
console.log(a);
a[0]['gender']='women'
a[0]['address']="China"
a[1].province="Jiangsu"
console.log(a);