php多个字符串替换成同一个的解决方法

<?php
$name = 'Today 3? , very/ cold';
$name = strtolower($name);
//$name = preg_replace('/[^a-z0-9\s]/','',$name);
$name = preg_replace('/[\.\s+\?,\/"]/','_',$name); //change spaces
echo $name;
?>

$name = preg_replace('/[\.\s+\?,\/"]/','_',$name); //change spaces