Find out the difference between undefined value vs undefined variable in JavaScript
Description
The following code shows how to find out the difference between undefined value vs undefined variable.
Example
<!-- w w w. ja v a2 s . c om-->
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
var aString;
document.writeln(aString); //"undefined"
document.writeln(anotherValue); //causes an error
</script>
</head>
<body>
</body>
</html>
The code above generates the following result.
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