js delete usage (delete object attributes and variables)_javascript skills

1, delete object attributes

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

Variables cannot be deleted directly using delelte

3, variables in the prototype chain cannot be deleted

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