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is_finite

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

is_finite — Checks whether a float is finite

Description

is_finite(float $num): bool

Returns whether the given num is a finite float.

A finite float is neither NAN (is_nan()), nor infinite (is_infinite()).

Parameters

num

The float to check

Return Values

true if num is none of NAN, INF, -INF, else false.

Examples

Example #1 is_finite() example

<?php
$float = 1.2345;
var_dump($float, is_finite($float));

$nan = sqrt(-1);
var_dump($nan, is_finite($nan));

$inf = 1e308 * 2;
var_dump($inf, is_finite($inf));
?>

The above example will output:

float(1.2345)
bool(true)
float(NAN)
bool(false)
float(INF)
bool(false)

See Also

© 1997–2025 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://www.php.net/manual/en/function.is-finite.php