(PHP)正则表达式-忽略大小写

<?php
/**
 * Created by PhpStorm.
 * User: Ollydebug
 * Date: 2015/11/15
 * Time: 15:20
 */

/*
 * U-懒惰匹配
 * i-忽略英文字母大小写
 * x-忽略空白
 * s-让元字符" . "匹配包括换行符内所有字符
 */

$pattern = "/GoOgle.+123/Ui";
$subject = "I love google__123123123123123123";

$matches = array();
preg_match($pattern,$subject,$matches);

show($matches);

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;
    }
}


?>