JS刪除對象中的某一屬性【轉】


JS如何刪除對象中的某一屬性

var obj={
	name: 'zhagnsan',
	age: 19 
}
delete obj.name //true
typeof obj.name //undefined

通過delete操作符, 可以實現對對象屬性的刪除操作, 返回值是布爾

可以刪除其他東西嗎
1.變量

var name ='zs'  //已聲明的變量
delete name  //false
console.log(typeof name)  //String

age = 19  //未聲明的變量
delete age	 //true
typeof age //undefined

this.val = 'fds'  //window下的變量
delete this.val	  //true
console.log(typeof this.val)  //undefined

已聲明的變量windows下的變量可以刪除, 未聲明的變量不可刪除

2.函數

var fn = function(){}  //已聲明的函數
delete fn	//false
console.log(typeof fn)  //function

fn = function(){}  //未聲明的函數
delete fn	//true
console.log(typeof fn)  //undefined

3.數組

var arr = ['1','2','3']  ///已聲明的數組
delete arr	//false
console.log(typeof arr)  //object

arr = ['1','2','3']  //未聲明的數組
delete arr   //true	
console.log(typeof arr)   //undefined

var arr = ['1','2','3']   //已聲明的數組
delete arr[1]  //true
console.log(arr)   //['1','empty','3'] 

4.對象

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

已聲明的對象不可刪除, 對象中的對象屬性可以刪除
 
文章轉自:https://blog.csdn.net/weixin_43553701/article/details/90757945


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