/*函数一 作用 排除 l代表排除指定字符串左边的，r代表排除指定字符串右边的*/
function paichu($mub,$zhi,$a){
    if(!$mub){
        return "被替换的字符串不存在";
    }
    $mub = mb_convert_encoding($mub,'GB2312','UTF-8');
    $zhi = mb_convert_encoding($zhi,'GB2312','UTF-8');
    if($a==""){
        $last = str_replace($mub,"",$zhi);
    }elseif($a=="r"){
        $last = preg_replace("/[".$mub."]+[\d\D\w\W\s\S]*/","",$zhi);
    }elseif($a=="l"){
        $last = preg_replace("/[\d\D\w\W\s\S]*[".$mub."]+/","",$zhi);
    }
    $last = mb_convert_encoding($last,'UTF-8','GB2312');
    return $last;
}
$mub = "情无";
$zhi = "随风舞动，心情无限!";
echo paichu($mub,$zhi,"l"); //输出： 随风舞动，心
echo paichu($mub,$zhi,"r"); //输出： 无!
echo paichu($mub,$zhi,""); //输出： 随风舞动，心限

来源：https://blog.csdn.net/weixin_39713538/article/details/116068536