JS刪除對象中的某一屬性

var obj = {
    name: "zhangsan",
    age: 19
}
delete obj.name //true
typeof obj // 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

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)

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