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javascriptarraysvariables
Alan A
Alan A

Reputation: 2551

Javascript array with custom variable indexing

Is it possible to set the custom index of an array with a variable.

for example:

var indexID = 5;
var temp = {
    indexID: new Array()
};

The above example sets the array index to indexID and not 5. I have tried using = snd quotes but I without any success.

Thnaks

Upvotes: 12

Views: 44062

Answers (6)

nihal malik
nihal malik

Reputation: 101

var index=7;  //YOUR CUSTOM INDEX
var newarray=[];

If you need array index to be an array you can do it like this:

newarray[index] = {
                   'KEY':'VAL',
                   'KEY':'VAL',
                   'KEY':'VAL'
                    }

If you need to assign just a value to your custom array index you can do it like this:

newarray[index] = "ANY-THING-YOU-WANT"

Upvotes: 0

ALI ALRIKABI
ALI ALRIKABI

Reputation: 3

for node-red project i had to add Apostrophe to the index name

var Trend_1={};

Trend_1[**'x'**]=Date_TimeArray;

Upvotes: 0

KooiInc
KooiInc

Reputation: 122916

You are mixing Array with Object. Arrays know a (numeric) index, Objects consist of key-value pairs, where key may be any string.

Not everyone would agree, bu you could extend Object.prototype

Object.prototype.append = function(key,val){
  // confine to Object instances
  if (this.constructor !== Object && 
      !/object/i.test(this.constructor.prototype)) { return this; }
  this[key] = val;
  return this;
}

And subsequently use:

var temp = {}.append(indexID,[]};

Upvotes: 0

Nick Fishman
Nick Fishman

Reputation: 654

I think what you want is:

var indexID = 5;
var temp = {};
temp[indexID] = "stuff"

Upvotes: 6

pvorb
pvorb

Reputation: 7279

With your code, you will create an object.

Instead you can do

var indexID = 5;
var temp = [];
temp[indexID] = [];

Upvotes: 1

VisioN
VisioN

Reputation: 145408

Yes, just use square brackets notation:

var temp = {};
temp[indexID] = [];

Also pay attention to the fact that temp is an object, and not an array. In JavaScript all associative arrays (or dictionaries) are represented as objects.

MORE: http://www.jibbering.com/faq/faq_notes/square_brackets.html#vId

Upvotes: 22

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