confusion with javascript prototype object

Question

when we create an object like this

function Person(first,last){
this.first = first;
this.last = last;
this.full = function (){
 alert(this.first + " " + this.last); 
 }
}
obj = new Person('abdul','raziq');

could we also add to obj's prototype anything like this

obj.prototype = 'some functions or anything ';

or its not possible once we created the object ?

and there is a __proto__ property on person object

obj.__proto__

but when i access obj.prototype property its undefined ?

can someone pls explain in a simple way possible

• Explosion Pills: The answer is yes, you can add to the prototype after an object instance is created.
• raziq ijr: i have modified my question pls read it once again
• raziq ijr: i want to add to obj prototype property , is it possible to add to obj prototype property something
• Arun P Johny: objects does not have prototype property
• Aadit M Shah: Only functions have a prototype property. Add it to the prototype of the constructor function instead.

Answer 1

The prototype property only exists on functions, not on instances of functions. Read this StackOverflow answer to know more: https://stackoverflow.com/a/8096017/783743

Answer 2

You can do something like

Person.prototype.full = function(){
 alert(this.first + " " + this.last); 
}

Demo: Fiddle

The prototype object is attached to the Class not to the instance so yes you can add/remove properties to/from prototype after instances are created. And all instances of the type will reflect the changes made.

• raziq ijr: sorry i have corrected my question pls read it once again thanks