March releases of Firefox and Chrome to support class, extends, constructor, super keywords in Javascript

[samlancashire]

Firefox 45 and Chrome 49 (both to be released in March) will have support for ECMAScript 6's class declaration, as well as constructor method, and super and extends keywords. This means we can now create classes in Javascript like this:

class Sprite {
    constructor(health) {
        this.health = health;
        this.maxHealth = health;
    }
    get totalDamageTaken() {
        return this.maxHealth - this.health;
    }
}

class Enemy extends Sprite {
    constructor(health, damage) {
        super(health);
        this.damage = damage;
    }
    attack(sprite) {
        sprite.health -= this.damage;
    }
}

var player = new Sprite(10);
var badguy = new Enemy(10, 2);

badguy.attack(player);
badguy.attack(player);

console.log(player.health, player.totalDamageTaken); // 6, 4

If you want to try for yourself you can download Firefox Developer Edition, as it currently supports these features.

For more information read MDN's documentation.

[rich]

Also https://kpdecker.github.io/six-speed

[dimumurray]

No support as of yet for ES6's new module system...bummer.

[Gugis]

Whaaaaat? I'm using ES6 ~6 months and it's already working on Chrome  What those releases will change?

[mattstyles]

2 hours ago, Gugis said:

Whaaaaat? I'm using ES6 ~6 months and it's already working on Chrome  What those releases will change?

If you are transpiling the browser never sees your ES2015 code.

Otherwise you are only using the stuff that Chrome has supported for those 6 months.