is_infinite() function in PHP

The is_infinite() function checks if a value is infinite or not. It returns true if the number is an infinite number, else it returns false.

Syntax

is_infinite(num)

Parameters

• num − The number to be checked.

Return Value

The is_infinite() function returns true if num is an infinite number, else it returns false.

Example 1: Finite Number

Let's check if a regular number is infinite ?

<?php
    echo is_infinite(1) ? 'true' : 'false';
?>

false

Example 2: Infinite Number

Here we use log(0) which produces negative infinity ?

<?php
    echo is_infinite(log(0)) ? 'true' : 'false';
?>

true

Example 3: Positive Infinity

We can also check for positive infinity using division by zero ?

<?php
    $positive_inf = 1/0;
    echo is_infinite($positive_inf) ? 'true' : 'false';
?>

true

Conclusion

The is_infinite() function is useful for checking mathematical operations that may result in infinite values. It returns true for both positive and negative infinity values.