str_replace 批量查找替換字符串

<?php
$str = 'I Love You!';
$str = str_replace('o','O',$str,$count);
echo $str.PHP_EOL; // I LOve YOu!

echo '替換了'.$count.'個'.PHP_EOL; // 替換了2個

$str = 'I Love You!';
$str = str_replace(['o','u'],'O',$str,$count);
echo $str.PHP_EOL; // I LOve YOO!

echo '替換了'.$count.'個'.PHP_EOL; // 替換了3個

非常的實用，方便。