js中删除数组或对象

Posted 2023-03-20

参考技术A 在vue中使用

vue.delete()

删除对象属性

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

例：      var obj=name: 'zhagnsan',age: 19

            delete obj.name //true

            typeof obj.name //undefined

同样可用于函数，数组，变量，对象，但对象不能删除，只能做到删除对象属性

删除变量

例： 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

删除数组

以声明数组返回false，未声明返回true

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']

删除函数

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

删除对象

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