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JavaScript

What is more efficient when we use constructors; a prototype or a referenced function?

Referenced Function

function diceRoll() {
  var randomNumber = Math.floor(Math.random() * this.sides) + 1;
  return randomNumber;
}

function Dice(sides) {
  this.sides = sides;
  this.roll = diceRoll;
}

var dice = new Dice(6);

Prototype

function Dice(sides) {
  this.sides = sides;
}

Dice.prototype.roll = function() {
  var randomNumber = Math.floor(Math.random() * this.sides) + 1;
  return randomNumber;
}

var dice = new Dice(6);

Thanks,
Yuval Blass.

@stevenparker

1 Answer

Hi yuvalblass,

If there is any actual difference between the two — in terms of time and space complexity — that difference will be negligible. I can't think of a single instance when such a trivial discrepancy would become a matter of concern to a JavaScript developer. After all, the two modes of creating object methods that you are comparing are essentially identical. I'd be interested in hearing if anyone has an actual answer for this though.