Are there any common pitfalls to avoid when using the usort function in PHP to sort arrays?

One common pitfall to avoid when using the usort function in PHP is not properly defining the comparison function. The comparison function should return -1 if the first argument is less than the second, 0 if they are equal, and 1 if the first argument is greater than the second. Failing to follow this convention can result in unexpected sorting behavior.

// Example of defining a proper comparison function for usort
function customCompare($a, $b) {
    if ($a < $b) {
        return -1;
    } elseif ($a > $b) {
        return 1;
    } else {
        return 0;
    }
}

// Example usage of usort with the custom comparison function
$array = [3, 1, 2];
usort($array, 'customCompare');
print_r($array);