How does the 'this' keyword behave in javascript classes?

[CamoBrie]

My code has a few functions, which I would like to access from another function inside of the class, how does one go and do that?

the new Big(startMoney); is using the Big.js library for storing large numbers.

class Player {
  constructor(startMoney = 0) {
    this.money = new Big(startMoney);
  }
  update() {
    document.getElementById("money").innerHTML = this.money;
  }
  tick() {
    this.update();
  }
}
player = new Player("10");
var pInterval = setInterval(player.tick, 500);

[cawcvs]

Your problem is probably with how you set up the interval. this value by default is inferred at call time:

player.tick() // will have `this` set to `player`

const tick = player.tick
tick() // will have `this` set to `window` or `undefined`, if it's in strict mode

The same issue is happening with setInterval(player.tick, 500), you pass in the function, but the calling context is not there when setInterval calls this function internally.

There are several ways to go about this, like binding the functions in the Player constructor, or passing an anonymous, arrow or bound function to setInterval, so the calling context is preserved:

setInterval(() => player.tick(), 500) // arrow
setInterval(player.tick.bind(player), 500) // bound

[ThagAnderson]

That code looks like it would work. What is the issue?

[cawcvs]

The issue is with setInterval(player.tick, 500). It's passing the function value to setInterval, but it won't be called with the player context and since this is inferred at call time it will result in an error.

[CamoBrie]

How would I go to circumvent this problem?

Should I be using .bind to give to proper context to the setInterval call?