Validate that Javascript variable present in source code

Question

Hi all,

Is it possible to fail a script if a javascript variable is not present in the source code of a page? How would this be done?

<html>
<head>
<title>My Page</title>
<script>
var myVar = Math.random() + "";
</script>
</head>
<body>...</body>
</html>

Assuming the above page, how would I check that myVar exists & if it doesn't, fail the script.

I've tried this example, this example, window.myVar, gomez_top[0].myVar with no joy.

I will fail the script using this method.

Answer 1

Answer by Brett B. · Aug 17, 2016 at 12:55 PM

Hey Adam,

Could you write a try/catch block around the line where you use the variable? Something like:

try{
	myVar = Math.random() + "";
}
catch(err){
	log(err.message)
}

I saw this w3schools example which changed the doc.innerHTML on a var not being set

0 · Share