Array within array

Question

I want to make an array within an array.

It would contain some enemies with all different positions. I tried writing it like this:

var enemies = [
    position = {
        x: 0,
        y: 0
    }
];
enemies.length = 6;

This seem to work, however, I don’t know what to write when I want to call it. enemies[1].position.x doesn’t work at all. Any leads?

`var enemies = [{x:0, y:0}, {x:5, y:5}, {x:10, y:10}];` then just refer to `enemies[index].x` — Abhitalks, Sep 15 '15 at 12:25
@Xufox How is that? Though it's not very common or recommended, it's valid syntax. — Teemu, Sep 15 '15 at 12:25
@Xufox It's not invalid, he's just creating a global (`position`). — Yoshi, Sep 15 '15 at 12:25
possible duplicate of [Access / process (nested) objects, arrays or JSON](http://stackoverflow.com/questions/11922383/access-process-nested-objects-arrays-or-json) — display name, Sep 15 '15 at 12:26
possible duplicate of [Javascript Array inside Array - how can i call child array name](http://stackoverflow.com/questions/9871634/javascript-array-inside-array-how-can-i-call-child-array-name) — Ulad Kasach, Sep 15 '15 at 12:27

Andy · Answer 1 · 2015-09-15T12:29:40.483

2

You probably want an array of enemy objects instead. Something like:

var enemies = [
    { position: { x: 0, y: 0 } },
    { position: { x: 0, y: 0 } },
    { position: { x: 0, y: 0 } }
];

var firstEnemy = enemies[0];

firstEnemy.position.x; // 0

var totalEnemies = enemies.length; // 3

edited Sep 15 '15 at 12:29

answered Sep 15 '15 at 12:25

Andy

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Thanks, @nikhil. Completely missed that. – Andy Sep 15 '15 at 12:29

score 1 · Answer 2 · answered Sep 15 '15 at 12:25

What you want to do is

var enemies =  [
    {
        position: { x: 0, y: 0 }
    }
];

enemies[0].position.x;

Arrays index starts from 0

Also, let's deconstruct why your code doesn't throw an error, and what it exactly does.

You are declaring an array named enemies, and when declaring it you are defining a global variable named position (and its value is returned)

After execution, enemies look like this [ {x: 0, y: 0} ]

Array within array

2 Answers2