1,对象属性删除
function fun(){this.name = 'mm';}var obj = new fun();console.log(obj.name);//mmdelete obj.name;console.log(obj.name); //undefined 2,变量删除
var name = 'lily';delete name;console.log(name); //lily
直接用delelte删除不了变量
3,删除不了原型链中的变量
fun.prototype.age = 18;delete obj.age;console.log(obj.age) //18
