JS Deleting an Attribute in an Object

The code is as follows

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

Through the delete operator, you can delete the object attributes, and the return value is Boolean

Can I delete anything else

1. Variables

var name ='zs' // Declared variables 
delete name //false
console.log(typeof name) //String

age = 19 // Undeclared variable 
delete age	 //true
typeof age //undefined

this.val = 'fds' //window Variables under 
delete this.val	 //true
console.log(typeof this.val) //undefined

The declared variables under windows can be deleted, but the undeclared variables cannot be deleted

2. Functions

var fn = function(){} // Declared functions 
delete fn	//false
console.log(typeof fn) //function

fn = function(){} // Undeclared function 
delete fn	//true
console.log(typeof fn) //undefined

3. Arrays

var arr = ['1','2','3'] /// Declared array 
delete arr //false
console.log(typeof arr) //object

arr = ['1','2','3'] // Undeclared array 
delete arr //true 
console.log(typeof arr) //undefined

var arr = ['1','2','3'] // Declared array 
delete arr[1] //true
console.log(arr) //['1','empty','3'] 

4. Objects

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

Declared objects cannot be deleted, and object properties in objects can be deleted