Creating javascript function with variable name and accessing it?

Question

i have a scenario where javascript function name needs to be decided at run time. For simplicity assume i have function name in javascript variable and now i want to create the function using variable value. I went thru the link Javascript - Variable in function name, possible? and tried the small code snippet

   <HTML>
       <HEAD>
          <TITLE> New Document </TITLE>
      </HEAD>
        <script>
        var temp1='at_26';
        temp1: function() {alert("Inside 26"); }
        </script>
         <BODY>
            <a href="javascript:window[at_26]()">Copy Text</a>
         </BODY>
    </HTML>

But when i click on hyperlink Copy Text it gives error saying Line: 1 Error: 'at_26' is undefined

The question you linked to does not show anything regarding `temp1: function() {alert("Inside 26"); }`. Where do you get this from? This is invalid JavaScript. — Felix Kling, Oct 13 '12 at 09:47

mplungjan · Accepted Answer · 2012-10-13T09:49:24.833

2

DEMOs

var temp1='at_26'; 
window[temp1]=function() {alert("Inside 26"); return false}

and then

<a href="#" onclick="return window['at_26']()">Click</a>

or

<a href="#" onclick="return at_26()">Click</a>

should work

What I THINK you want since it does not pollute the global scope and is using a colon like in your example is this:

var myScope = {
  "at_26":function() {alert("Inside 26"); return false}
}

using

<a href="#" onclick="return myScope.at_26()">Click</a><br />

edited Oct 13 '12 at 09:49

answered Oct 13 '12 at 09:34

mplungjan

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Yes, it is. `window[temp1]` resolves as `window['at_26']`, and the function is assigned there. Nowhere do you say `window['temp1'] = function` or `temp1 = function`. – Quentin Oct 13 '12 at 09:42

score 1 · Answer 2 · answered Oct 13 '12 at 09:27

1

There were multiple issues in your code. A corrected version will be like:

<script>
    window['at_26'] = function() {alert("Inside 26"); };
</script>
<BODY>
    <a href="javascript:window['at_26']()">Copy Text</a>
</BODY>

answered Oct 13 '12 at 09:27

techfoobar

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Why the downvote (apart from not fixing the horrible javascript pseudo protocol) – mplungjan Oct 13 '12 at 09:29
@techfoobar my question is creating the function name with variable name.you have hardcoded the function name with window['at_26'] = function() {alert("Inside 26"); }; – M Sach Oct 13 '12 at 09:44
@MSach: You can almost always replace any literal with a variable. If `var a = 'at_26';` then you can write `window[a] = ...;` and `window[a]();`. No big deal. – Felix Kling Oct 13 '12 at 09:48

Creating javascript function with variable name and accessing it?

2 Answers2