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);//mmdelete obj.name;console.log(obj.name); //undefined

2. Variable deletion

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

Can't 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