CODEWITHSUNDEEP
javascriptconstructorprototype
Elangovan Nagarajan
Elangovan Nagarajan

Reputation: 17

JS: Is there a difference between class.prototype.constructor and class.constructor

In a tutorial I am reading, there is a part I don't understand:

function User (theName, theEmail) {
    this.name = theName;
    this.email = theEmail;
    this.quizScores = [];
    this.currentScore = 0;
}
​
User.prototype = {
    constructor: User,
    saveScore:function (theScoreToAdd)  {
        this.quizScores.push(theScoreToAdd)
    },
    showNameAndScores:function ()  {
        var scores = this.quizScores.length > 0 ? this.quizScores.join(",") : "No Scores Yet";
        return this.name + " Scores: " + scores;
    },
    changeEmail:function (newEmail)  {
        this.email = newEmail;
        return "New Email Saved: " + this.email;
    }
}

I have read the post and checked the web but I don't really understand, is there a difference between saying: User.constructor and User.prototype.constructor? (Like on Line 9)

Upvotes: 0

Views: 67

Answers (2)

user3045179
user3045179

Reputation: 331

When you are doing

user.prototype={},

You are actually creating new object. So it will be

user.prototype=new Object()

and its constructor will change to Object, so to keep constructor to user object

 constructor: User

and constructor is property of prototype. To call constructor from class user, you need to create new instance of class user then only you can use constructor property directly

Upvotes: 1

meskobalazs
meskobalazs

Reputation: 16041

The User.constructor sets the constructor of the User instance. The User.prototype.constructor sets the constructor of all instances. Thus if you set

User.prototype.constructor = function test(){};

then

new User().constructor

will also be the test function.

Upvotes: 1

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