getting values of eval()'d variable names..

**jumboshrimp** · Oct 15, 2007, 10:12

i'm setting string variables using eval. But when i check their type i get back "object". The string inside eval evaluates to: var the_variable = "value";

so i can't understand why the type would say object. does anyone know if this is common behavior?

**jimfraser** · Oct 15, 2007, 10:23

This gives me "string":

Code:

<html>
<head>
<script type="text/javascript">
window.onload = function () {
	var someText = "var myVar = 'testing 1.2.3';";
	eval(someText);
	alert(typeof myVar);
}	
</script>
</head>
<body>
</body>
</html>

**jumboshrimp** · Oct 15, 2007, 10:27

i just got the same result.. I realized what i was doing. I wasn't doing the typeof inside the function i was doing the eval in. For some reason i was assuming that i was setting the eval'd variables globally. So, What would be the best way to get these variables global? declaring a "mother" array or object in the global scope? or is there a way to make these variables available outside the function?

Thanks for the help!

**jimfraser** · Oct 15, 2007, 10:50

You can do it without using eval at all - create properties of the window object and then you can reference them no matter which function you're in:

Code:

window.onload = function () {
	window["myVar"] = "testing 1.2.3";
	window["some other variable"] = "other ting";
	
	alert(typeof window["some other variable"]);
	alert(typeof window["myVar"]);
}

**jumboshrimp** · Oct 15, 2007, 11:02

i'm using eval because i don't know what my variable names are going to be. My statement looks like this:

Code JAVASCRIPT:

eval('var '+to_be_determined+' = "'+some_value+'";');

**jimfraser** · Oct 15, 2007, 11:05

You can do the same thing without eval

Code:

// example
var to_be_determined = "this is some variable name";

window[to_be_determined] = some_value;

**jumboshrimp** · Oct 15, 2007, 11:46

that's what i ended up doing. thanks for the help jim.

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