js delete usage (delete object properties and variables)

1, Object attribute deletion

function fun(){
 
this.name = 'mm';
 
}
 
var obj = new fun();
 
console.log(obj.name);//mm
 
delete obj.name;
 
console.log(obj.name); //undefined

2, Variable deletion

var name = 'lily';
delete name;
console.log(name); //lily

You cannot delete variables directly with delelte

3. The variables in the prototype chain cannot be deleted

fun.prototype.age = 18;
delete obj.age;
console.log(obj.age) //18

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