check if js variable is set

[elliottmina]

What is the best way to check if a variable is set? If it unset, then I can check its length, but I haven't been able to find any functions like empty(), isset(), etc.

TIA

 

[jemminger]

here's a rudimentary way:

<script type="text/javascript">
	if (isset("foo")) {
		alert("yes foo");
	}
	else {
		alert("no foo");
	}

	function isset(sVarName) {
		return window[sVarName] != null;
	}
</script>

-jeff

http://www.jeffemminger.com

try { succeed(); } catch(E) { tryAgain(); } finally { rtfm(); }
i like your sleeves...they're real big

 

[elliottmina]

Thank you!