index.toString() problem

Phaser 3
1

Hi there, I am trying to spawn several enemies using a loop method however I keep getting an error called Cannot read property ‘toString’ of undefined.

Here is where I have called my spawn of enemies:

enemyPlayer = function (index, game, player, x, y, bullets) {

var x = Phaser.Math.RND.between(0, 800);
var y = Phaser.Math.RND.between(0, 600);

  this.game = game;
  this.tank.name = index.toString();
  this.health = 3;
  this.player = player;
  this.bullets = bullets;
  this.fireRate = 1000;
  this.nextFire = 0;
  this.alive = true;

  this.tank = this.physics.add.sprite(x, y, 'enemy', 'tank1').setOrigin(0.5, 0.5);
  this.turret = this.physics.add.sprite(x, y, 'enemy', 'turret').setOrigin(0.3, 0.5);
  //this.physics.world.enable(this.tank);

  this.tank.body.immovable = false;
  this.turret.body.immovable = false;
  this.tank.body.collideWorldBounds = true;
  this.turret.body.collideWorldBounds = true;
  this.tank.body.bounce.setTo(1, 1);
  this.turret.body.bounce.setTo(1, 1);

  this.physics.velocityFromRotation(this.tank.rotation, 100, this.tank.body.velocity);
  this.physics.velocityFromRotation(this.tank.rotation, 100, this.turret.body.velocity);

};

And this is in my create function:

enemies = [];

        enemiesTotal = 20;
        enemiesAlive = 20;

        for (var i = 0; i < enemiesTotal; i++)
        {
            enemies.push(enemyPlayer.call(i, game, tank, 0, 0, this));
        }
2

Hey Faizan, it’s telling you that your parameter, index is undefined (Likely null). console.log your first argument, index to see.

3

Hey Jake, it’s telling me that index is undefined.

4

That means when you create your enemyPlayer, index was never assigned a value. If you only have one enemy tank, then I would simply change

this.tank.name = index.toString();

to something like

this.tank.name = "myTank";

5

Sorry I don’t quite understand, if I want to create an array that will create my enemies how would I call the index?

E.g. how will I call the 20 enemies here:

enemies = [];

        enemiesTotal = 20;
        enemiesAlive = 20;

        for (var i = 0; i < enemiesTotal; i++)
        {
            enemies.push(enemyPlayer.call(i, game, tank, 0, 0, this));
        }
6 
function enemyPlayer (
  index,
  game,
  player,
  x,
  y,
  bullets,
  scene
) {

  var x = Phaser.Math.RND.between(0, 800);
  var y = Phaser.Math.RND.between(0, 600);

  this.game = game;
  this.tank.name = index.toString();
  this.health = 3;
  this.player = player;
  this.bullets = bullets;
  this.fireRate = 1000;
  this.nextFire = 0;
  this.alive = true;

  this.tank = scene.physics.add.sprite(x, y, 'enemy', 'tank1').setOrigin(0.5, 0.5);
  this.turret = scene.physics.add.sprite(x, y, 'enemy', 'turret').setOrigin(0.3, 0.5);
  //scene.physics.world.enable(this.tank);

  this.tank.body.immovable = false;
  this.turret.body.immovable = false;
  this.tank.body.collideWorldBounds = true;
  this.turret.body.collideWorldBounds = true;
  this.tank.body.bounce.setTo(1, 1);
  this.turret.body.bounce.setTo(1, 1);

  scene.physics.velocityFromRotation(this.tank.rotation, 100, this.tank.body.velocity);
  scene.physics.velocityFromRotation(this.tank.rotation, 100, this.turret.body.velocity);
};

// …

enemies.push(
  new enemyPlayer(
    i,
    game,
    tank,
    0,
    0,
    bullets,
    this
  )
);