(PHP)正则表达式-preg_match和preg_match_all()的用法

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

/*
 * preg_match()第三个参数可选，第三个参数是引用传递,它在匹配subject的时候，只会匹配一次
 * preg_match_all()第三个参数必填,第三个参数也是引用传递，它在匹配subject的时候，会把所有满足条件的结果都匹配出来
 */

$pattern = &#39;/[0-9]/&#39;;
$subject = &#39;weuyr3ui76as83s0ck9&#39;;
$m1 = $m2 = array();
$t1 = preg_match($pattern,$subject,$m1);
$t2 = preg_match_all($pattern,$subject,$m2);

show($m1);
echo &#39;<hr/>&#39;;
show($m2);
echo &#39;<hr/>&#39;;
show($t1.&#39;||&#39;.$t2);

function show($var){
    if(empty($var)){
        echo &#39;null&#39;;
    }elseif(is_array($var)||is_object($var)){
        // array,object
        echo &#39;<pre class="brush:php;toolbar:false">&#39;;
        print_r($var);
        echo &#39;