How to use a string as a variable name in Javascript? [duplicate]

Question

Possible Duplicates:
Is there a way to access a javascript variable using a string that contains the name of the variable?
JavaScript: Get local variable dynamicly by name string

A simple code to illustrate my problem -

var chat_1 = "one";

var chat_2 = "two";

var id = "1";

var new = ?? variabalize( 'chat_' + id )

I want the variable new to be assigned the value of variable - chat_1 which is "one"

Variable variables are not good practice. Consider using an array instead. — Pekka
– Pekka, Commented May 28, 2011 at 6:55
Dup of Is there a way to access a javascript variable using a string that contains the name of the variable?, Javascript using variable as array name, How can I access local scope dynamically in javascript? — outis
– outis, Commented May 28, 2011 at 7:02
... Convert string to variable name in Javascript, How to find JavaScript variable by its name, how to use variable in a variable name, Javascript: Get access to local variable or variable in closure by its name — outis
– outis, Commented May 28, 2011 at 7:06
... Javascript Variable Variables, “Variable” Variables in Javascript?, Variable assignment in JavaScript, ... I give up. — outis
– outis, Commented May 28, 2011 at 7:09

Quentin · Accepted Answer · 2011-05-28 06:58:00Z

27

Stop. Reorganise your code. If you want to select variables with a variable, then there has to be a logical grouping for them. Make it explicit.

var chat = {
    "1": "one",
    "2": "two"
};
var id = 1;
var new_is_a_keyword_and_cant_be_an_identifier = chat[id];

answered May 28, 2011 at 6:58

Quentin

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1 Comment

Sussagittikasusa Over a year ago

Hey thank you for replying, this looks live a very nice way of doing what I wanted. Also how do I add more "keys"/variables to this main chat variable?

Ben G · Accepted Answer · 2011-05-28 06:56:58Z

6

This is not a good practice, but you can do it as follows:

var i=1;
//window['name' + i] will now access the variable

Source: http://www.i-marco.nl/weblog/archive/2007/06/14/variable_variables_in_javascri

answered May 28, 2011 at 6:56

Ben G

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1 Comment

user166390 Over a year ago

+1 But I would emphasis NOT GOOD PRACTICE. Most of the time code like this is a result of coming from certain "other" languages... It must be pointed out this only works on "global variables" and will not work for variables defined within a function.

Russell Davis · Accepted Answer · 2011-05-28 07:04:57Z

2

You can use the global window object, assuming these are not defined inside a function:

var new = window['chat_' + id];

edited May 28, 2011 at 7:04

answered May 28, 2011 at 6:56

Russell Davis

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3 Comments

Quentin Over a year ago

They are locally scoped variables. That won't work inside a function.

user166390 Over a year ago

@Quentin They may be locally scoped (and the second statement holds). However, the question is vague on this and it will work for "global variables".

shanusmagnus Over a year ago

+1 for answering the question. Providing warnings and context is fine, but I hate it when people give lectures instead of answering the question.

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