<!DOCTYPE html>
<html>
<body>
<h1>JavaScript Global Methods</h1>
<h2>The isNaN() Method</h2>
<p>isNaN() returns true if a value is NaN:</p>
<p id="demo"></p>
<script>
let result =
"Is 123 NaN? " + isNaN(12) + "<br>" +
"Is -1.23 NaN? " + isNaN(-1) + "<br>" +
"undefined value ? " + isNaN(undefined) + "<br>" +
"empty value ? " + isNaN();
document.getElementById("demo").innerHTML = result;
</script>
</body>
</html>
Output:
Use of isNaN() method? how to check variable has value or not?
Working Code Asked question July 5, 2023