代码如下
var obj={
name: 'zhagnsan',
age: 19
}
delete obj.name //true
typeof obj.name //undefined
通过delete操作符, 可以实现对对象属性的删除操作, 返回值是布尔
可以删除其他东西吗
1.变量
var name ='zs' //已声明的变量 delete name //false console.log(typeof name) //String age = 19 //未声明的变量 delete age //true typeof age //undefined this.val = 'fds' //window下的变量 delete this.val //true console.log(typeof this.val) //undefined
已声明的变量windows下的变量可以删除, 未声明的变量不可删除
2.函数
var fn = function(){} //已声明的函数
delete fn //false
console.log(typeof fn) //function
fn = function(){} //未声明的函数
delete fn //true
console.log(typeof fn) //undefined
3.数组
var arr = ['1','2','3'] ///已声明的数组 delete arr //false console.log(typeof arr) //object arr = ['1','2','3'] //未声明的数组 delete arr //true console.log(typeof arr) //undefined var arr = ['1','2','3'] //已声明的数组 delete arr[1] //true console.log(arr) //['1','empty','3']
4.对象
var person = {
height: 180,
long: 180,
weight: 180,
hobby: {
ball: 'good',
music: 'nice'
}
}
delete person ///false
console.log(typeof person) //object
var person = {
height: 180,
long: 180,
weight: 180,
hobby: {
ball: 'good',
music: 'nice'
}
}
delete person.hobby ///true
console.log(typeof person.hobby) //undefined
已声明的对象不可删除, 对象中的对象属性可以删除
