Definition and Usage
The isNaN() function is used to check if a value is not a number.
Syntax
| Parameter | Description |
| number | Required. The value to be tested |
Example
In this example we use isNaN() to check some values:
<script type="text/javascript"> document.write(isNaN(123)+ "<br />");
document.write(isNaN(-1.23)+ "<br />");
document.write(isNaN(5-2)+ "<br />");
document.write(isNaN(0)+ "<br />");
document.write(isNaN("Hello")+ "<br />");
document.write(isNaN("2005/12/12")+ "<br />");</script> |
The output of the code above will be:
false
false
false
false
true
true |
