Human implode

helpers.php

<?php 

function human_implode($glue = ",", $last = "y", $elements = array(), $filter = null){

	if ($filter) {
		$elements = array_map($filter, $elements);
	}

	$str = implode("{$glue} ", $elements);
	
	if (count($elements) == 2) {
		return str_replace("{$glue} ", " {$last} ", $str);
	}

	return preg_replace("/[{$glue}](?!.*[{$glue}])/", " {$last}", $str);
}

index.php

<?php

require 'helpers.php';

print_r("<pre>");
print_r(human_implode(",", "y", ["Hugo", "Paco", "Luis"]));
print_r("<br>");
print_r(human_implode(",", "y", ["limón sin semilla", "melón chino", "jitomate saladette"], "ucfirst"));
print_r("<br>");
print_r(human_implode(",", "y", ["chalequito matón", "pantaloncito trucutrú"], "ucwords"));
print_r("<br>");
print_r(human_implode(",", "o", ["Guillermo Ochoa", "José de Jesús Corona", "Alfredo Talavera"], "mb_strtoupper"));
print_r("</pre>");