Question

I cannot get this to work:

var global_variables = {
    players: []
}; 

var player = function(properties){
    this.width = properties.width;                            
    this.height = properties.height;
    this.position = properties.position;
    this.position.x = properties.position.x;
    this.position.y = properties.position.y;
}

function load_players(){
    global_variables.players.push(
        [
            new player(
                {
                    width: 10,
                    height: 10,
                    position: {
                        x: 50,
                        y: 50
                    },
                    colour: '#ff0000'
                }
            )
        ]
    );
}


 function init(){ 
    var ctx = load_canvas();
    load_players();

    for(a in global_variables.players){
        var _this = global_variables.players[a];
        alert(_this.colour);
    }
}

alert(_this.colour) just alerts undefined. Any ideas?

Answer 1

1. You were trying to loop before calling init
2. You were pushing your player instance wrapped in an array. You just wanted to push the player.
3. Don’t use for ... in ... on an array. Use a regular loop or use forEach like I did.
4. You were never actually setting the colour property to your instance.

http://jsfiddle.net/GLsR2/

Here’s the code from the fiddle:

var global_variables = {
    players: []
}; 

var player = function(properties){
    this.width = properties.width;                            
    this.height = properties.height;
    this.position = properties.position;
    this.position.x = properties.position.x;
    this.position.y = properties.position.y;
    this.colour = properties.colour;
}

function load_players(){
    global_variables.players.push(
        new player(
                {
                    width: 10,
                    height: 10,
                    position: {
                        x: 50,
                        y: 50
                    },
                    colour: '#ff0000'
                }
            )
      );
}


init();

global_variables.players.forEach(function(player) {
   alert(player.colour); 
});

function init(){ 
    load_players();
}