Why am I unable to delete a getter function from an object instance?

Question

I am confused as to why I am unable to delete a getter function from an object instance of a constructor function:

//created constructor function
let f = function () {
    this.a = 1;
    this.b = 2;   
}
    
//created an instance
let o = new f()
    
//created a getter function on object o

Object.defineProperties(o, {f: 
    {get: function(){
    return 100
    }
}})
        
//tried to delete but got response as false.
delete o.f

Answer 1

You can only delete configurable properties. From MDN:

configurable
true if the type of this property descriptor may be changed and if the property may be deleted from the corresponding object. Defaults to false .

 //created constructor function let f = function () { this.a = 1; this.b = 2; } //created an instance let o = new f() //created a getter function on object o Object.defineProperties(o, { f: { get: function(){ return 100 }, configurable: true, } }) console.log(delete of);

Answer 2

That's because you didn't set the f property as configurable :

 //created constructor function let f = function () { this.a = 1; this.b = 2; } //created an instance let o = new f() //created a getter function on object o Object.defineProperties(o, { f: { get: function(){ return 100 }, configurable: true } }); //tried to delete but got response as false. console.log(delete of); console.log(of);