请写出下述的打印结果

var a = 1
var b = a
b+=2
console.log(a,b)
结果==>1,3



var obj = {
	name:"zhangsan",
	age:12
}
var obj2 = obj;
console.log(obj,obj2);
结果==>name:"zhangsan",
	age:12
               name:"zhangsan",
	age:12

obj2.gender = "male";
console.log(obj,obj2);
结果==>name:"zhangsan",
	age:12,
               gender:"male"
              name:"zhangsan",
	age:12,
               gender:"male"

obj2.age+=1
console.log(obj,obj2)
结果==>name:"zhangsan",
	age:13,
               gender:"male"

name:"zhangsan",
	age:13,
               gender:"male"