Simple censor for sensitive data

censor.php

<?php
/**
 * Censor the part of string
 *
 * @param mixed $str
 * @param mixed $mask
 * @param int $intensity
 * @param int $reveal
 * @return string
 */

function censor(mixed $str, mixed $mask = '*', int $intensity = 2, int $reveal = 2) {
	return substr_replace(
		$str,

		str_repeat(
			$mask, (
				(strlen($str) - $intensity) >= 0
			) ? (
				strlen($str) - $intensity
			)
		: 1),

	$reveal);
}