(PHP)正则表达式-preg_replace()和preg_filter()

<?php
/**
* 正则表达式练习
* User: Ollydebug
* Date: 2015/11/13
* Time: 13:28
*/

/*
* preg_replace()不论发不发生替换，值都保留.
* preg_filter()只保留发生替换的值.
*/

$pattern = array('/[0123]/','/[456]/','/[789]/');
$subject = array("weuy","r3ui","76as83","s","0ck9");
$replacement = array('百','小','度');
$str1 = preg_replace($pattern,$replacement,$subject);
$str2 = preg_filter($pattern,$replacement,$subject);

show($str1);
echo '<hr/>';
show($str2);

function show($var){
if(empty($var)){
echo 'null';
}elseif(is_array($var)||is_object($var)){
// array,object
echo '<pre>';
print_r($var);
echo '</pre>';
}else{
//string,int,float
echo $var;
}
}

?>