js delete 用法(删除对象属性及变量)

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



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