Javascript OOP Constructor with array or sub-object?

Question

I am new to true OOP but I understand javascript pretty alright. I'm trying to make new objects using a constructor pattern but I would like to make one of the properties an array.

Here's an example of what I'm trying to do:

function Walker(name, type, ws, bs, s, armor, i, a, hp) {
    this.name = name;
    this.type = type;
    this.ws = ws;
    this.bs = bs;
    this.s = s;
    this.armor = new Array("f", "s", "r");
    this.i = i;
    this.a = a;
    this.hp = hp;
}

This is for a game some of you might know (and only for personal use, as the company who created the game has a stick up their... for their IP)

As you can see, the armor property is going to have 3 properties inside of it. The reason I'm doing it this way is because there is already a property named s, so I don't want that property and the armor property of s to be mixed up.

I am making a new walker and trying to log the armor like below:

var specificWalker = new Walker("Specific Walker", "Vehicle", 5, 5, 6, [12, 12, 10], 4, 2, 3);

console.log(specificWalker.armor[0]);

Though, of course this isn't working because armor[0] is always equal to "f" and I don't know how to override that that part of the array.

Ideally, what I would like to do is be able to log the armor this way:

console.log(specificWalker.armor.f) //Should log "12"

But I'm unsure on how to make an object inside of an object.

Can anyone help on this one?

possible duplicate of [Merge keys array and values array into an object in Javascript](http://stackoverflow.com/questions/1117916/merge-keys-array-and-values-array-into-an-object-in-javascript) — Joniras, Feb 25 '15 at 15:51

score 3 · Accepted Answer · answered Feb 25 '15 at 15:50

3

You just need to create an Object, instead of an Array, like this

this.armor = ["f", "s", "r"].reduce(function(result, current, index) {
    result[current] = armor[index];
    return result;
}, {});

Now, this.armor is not an Array, but an Object. When you print specificWalker.armor, you will get something like this

{ f: 12, s: 12, r: 10 }

and then you can access f, like you wanted

console.log(specificWalker.armor.f);
// 12

answered Feb 25 '15 at 15:50

thefourtheye

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Perfectly simple. Worked like a charm! I will have to look into the `.reduce` function. I've never come across that. @AmitJoki, This is actually exactly what I asked for in the bolded text. `specificWalker.armor.f` is all I need to type to log it out. Thank you! – ntgCleaner Feb 25 '15 at 15:54
@ntgCleaner Please check the [`Array.prototype.reduce`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce)'s official documentation, for explanation and examples :) – thefourtheye Feb 25 '15 at 15:56

Santiago Hernández · Answer 2 · 2015-02-25T17:08:51.787

i think you have so many arguments on the constructor, i'd do it this way:

function Walker(prop) {
    this.name = prop.name;
    this.type = prop.type;
    this.ws = prop.ws;
    this.bs = prop.bs;
    this.s = prop.s;
    this.armor = prop.armor;
    this.i = prop.i;
    this.a = prop.a;
    this.hp = prop.hp;
}

and call it this way

var walker = new Walker({
    name : "",
    type : "",
    ws : "",
    bs : "",
    s : "",
    armor : [12,12,39],
    i : "",
    a : "",
    hp : ""
});

Javascript OOP Constructor with array or sub-object?

2 Answers2