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JavaScript isFinite() Function
JavaScript Global Functions
Definition and Usage
The isFinite() function determines whether a number is a finite, legal number.
Tip: This function returns false if the value is +infinity, -infinity, or NaN.
Syntax
isFinite(value)
| Parameter | Description |
|---|---|
| value | Required. The value to be tested |
Browser Support
The isFinite() function is supported in all major browsers.
Example
Example
Check whether a number is a finite, legal number:
<script>
document.write(isFinite(123)+ "<br>");
document.write(isFinite(-1.23)+ "<br>");
document.write(isFinite(5-2)+ "<br>");
document.write(isFinite(0)+ "<br>");
document.write(isFinite("Hello")+ "<br>");
document.write(isFinite("2005/12/12")+ "<br>");
</script>
document.write(isFinite(123)+ "<br>");
document.write(isFinite(-1.23)+ "<br>");
document.write(isFinite(5-2)+ "<br>");
document.write(isFinite(0)+ "<br>");
document.write(isFinite("Hello")+ "<br>");
document.write(isFinite("2005/12/12")+ "<br>");
</script>
The output of the code above will be:
true
true
true
true
false
false
true
true
true
false
false
Try it yourself »
JavaScript Global Functions
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