preg_match()与preg_match_all()

<?php
// 显示汉字
header('content-type: text/html;charset = utf-8');

/*    preg_match($pattern, $subject, [array &$matches]) 第三个参数可选，也是引用参数
    preg_match_all($pattern, $subject, array &$matches)

    return 匹配到结果的次数;
*/
    $pattern = '/[0-9]/';
    $subject = 'weuyr3ui76as83s0ck9';

    $m1 = $m2 = array();

    $t1 = preg_match($pattern, $subject, $m1);
    $t2 = preg_match_all($pattern, $subject, $m2);

    show($m1);
    echo '<hr />';
    show($m2);
    echo '<hr />';
    echo '$t1 & $t2 的返回值：';
    show($t1.'||'.$t2);

// 对输出做个判断，选择合适的输出方式
function show($var = null){
    if(empty($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;
    }
}