1,对象属性删除 function fun(){ this.name = ‘mm‘; } var obj = new fun(); console.log(obj.name);//mm delete 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
原文：http://www.cnblogs.com/youmingkuang/p/6506496.html