WordPress at a glance
function is not described

getid3_id3v2::IsANumber() public WP 1.0

{} It's a method of the class: getid3_id3v2{}

No Hooks.

Return

true|false.

Usage

$result = getid3_id3v2::IsANumber( $numberstring, $allowdecimal, $allownegative );
$numberstring(string) (required)
-
$allowdecimal *(true false)*
$allownegative *(true false)*

Code of getid3_id3v2::IsANumber() WP 5.7.2

<?php
public static function IsANumber($numberstring, $allowdecimal=false, $allownegative=false) {
	for ($i = 0; $i < strlen($numberstring); $i++) {
		if ((chr($numberstring[$i]) < chr('0')) || (chr($numberstring[$i]) > chr('9'))) {
			if (($numberstring[$i] == '.') && $allowdecimal) {
				// allowed
			} elseif (($numberstring[$i] == '-') && $allownegative && ($i == 0)) {
				// allowed
			} else {
				return false;
			}
		}
	}
	return true;
}