is there a way to declare a variable using the value of a functions parameter

Question

I need to declare a variable using a name that is sent through a function as a parameter/argument

function CreateDroptable(npcName) {
    Droptable.npcName = new Droptable();
}

what I want this to do is if typed "CreateDroptable(goblin)" it would create the variable "Droptable.goblin" but instead it declares it like "Droptable.npcName"

Is there anyway to fix it?

http://stackoverflow.com/questions/5613834/convert-string-to-variable-name-in-javascript — ROMANIA_engineer, Feb 17 '15 at 22:24

Jesse Kernaghan · Accepted Answer · 2015-02-17T22:30:00.350

1

function CreateDroptable(npcName) {
    Droptable[npcName] = new Droptable();
}

should do the trick. String/array/bracket notation is there for this very reason. :)

Edit:

I noticed that you mentioned using it accordingly: CreateDroptable(goblin) which will not work as is. it should be utilized like so:

CreateDroptable("goblin");

where goblin is a string, rather than a variable.

edited Feb 17 '15 at 22:30

answered Feb 17 '15 at 22:22

Jesse Kernaghan

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@jonaskjellerup could you repost the error you're getting? It didn't show up when you commented. – Jesse Kernaghan Feb 17 '15 at 22:26
found the problem is that i forgot to remove the "." before the "[" but again gives the same problem as the solution below – jonas kjellerup Feb 17 '15 at 22:33
@jonaskjellerup I'm not sure I understand the problem, what is the array you are referring to? All this does is creates a key on your current `Droptable` object with the value being a new Droptable object. – Jesse Kernaghan Feb 17 '15 at 22:37
The arrays are in the object Droptable but i figured out the problem with that – jonas kjellerup Feb 17 '15 at 22:43

score 0 · Answer 2 · answered Feb 17 '15 at 22:23

0

Try ...

function CreateDroptable(npcName) {
  Dreoptable[npcName] = new Droptable();
}

Then, when declaring ...

CreateDroptable("goblin");

Calling becomes ...

Droptable["goblin"](1,2,3);

answered Feb 17 '15 at 22:23

rfornal

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this kinda works but it doesn't because the Droptable is a object and this solution makes the arrays work as normal variables – jonas kjellerup Feb 17 '15 at 22:31

maxtuzz · Answer 3 · 2015-02-18T02:29:22.050

If you want to use straight objects instead of variables/arrays. Then you have to go object-orientated route - which is a bit different to what you have done.

function npc(type, health, strength) {
    this.type= type;
    this.health= health;
    this.strength= strength;
}

var goblin= new npc("Goblin", 100, 50);
var bat = new npc("Bat", 65, 1);

This overall looks a lot cleaner, and is the conventional way of doing things. But it may not be entirely what you are looking for.

Hope it helps nonetheless.

Happy coding!

is there a way to declare a variable using the value of a functions parameter

3 Answers3