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JavaScript Object-Oriented JavaScript: Challenge Building Constructor Methods and Generating Objects Game Class Constructor Method Solution

Posted by raul montes
raul montes
134 Points

Why the constructor method of the class Game is not including the properties board and players?

Hello, I still don't understand why in the constructor method there are not arguments. My code is as follows including both arguments. Can somebody explain me please?

constructor(board, players) {
  this.board = new Board();
  this.players = this.createPlayers();
  this.ready = false;
}

Thanks

2 Answers

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

You have listed two parameters, but neither of them is used in code in the body of the constructor. So they can both be omitted. None are needed because the code in the body of the method has everything it needs already to establish three values for the instance (board, players, and ready).

Trevor Maltbie
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.a{fill-rule:evenodd;}techdegree seal-36
Trevor Maltbie
Full Stack JavaScript Techdegree Graduate 17,021 Points
Trevor Maltbie
.a{fill-rule:evenodd;}techdegree seal-36
Trevor Maltbie
Full Stack JavaScript Techdegree Graduate 17,021 Points

I think I still don't understand all the JS jargon yet. Because none of the parameters are used inside the constructor they don't need to be passed as arguments? How is that different from the Player class where none of the parameters are reference again before the constructor curly braces close?

class Player {
    constructor(name, id, color, active = false) {
        this.name = name;
        this.id = id;
        this.color = color;
        this.active = active;
        this.tokens = this.createTokens(21);
    }
Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

In the "Player" example shown here, all constructor parameters are referenced in the code body.

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

This is an intermediate-level course. Have you already done the Beginning JavaScript track or an equvalent? The basics of function parameters would be covered in those courses.

Trevor Maltbie
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Trevor Maltbie
Full Stack JavaScript Techdegree Graduate 17,021 Points
Trevor Maltbie
.a{fill-rule:evenodd;}techdegree seal-36
Trevor Maltbie
Full Stack JavaScript Techdegree Graduate 17,021 Points

Ooooh boy this is embarrassing, Steven. I very much have completed those courses and I'm on Unit 4 of the FSJS TechDegree. I just cannot seem to wrap my head around OOJS (or maybe just "JS"! T_T). I just don't see the difference between a constructor like so:

constructor(name, id, color, active = false) {
        this.name = name;
        this.id = id;
        this.color = color;
        this.active = active;
        this.tokens = this.createTokens(21);

and one like this:

constructor() {
      this.board = new Board()
      this.players = this.createPlayers()
      this.ready = false
    }

one has no parameters and the other does, but I'm not sure why. this.name = name so it needs parameter? but this.board = new Board() so I guess since it's not this.board = board it doesn't need a parameter? Ooof. I'm starting to feel a bit stupid.

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

Seems like you have the right idea.. If the constructor was referencing "board", then "board" would need to come in as a parameter (or be a global).