php中文字符怎么转换成数字

function cn2num($string){
    if(is_numeric($string)){
        return $string;
    }
    // '仟' => '千','佰' => '百','拾' => '十',
    $string = str_replace('仟', '千', $string);
    $string = str_replace('佰', '百', $string);
    $string = str_replace('拾', '十', $string);
    $num = 0;
    $wan = explode('万', $string);
    if (count($wan) > 1) {
        $num += cn2num($wan[0]) * 10000;
        $string = $wan[1];
    }
    $qian = explode('千', $string);
    if (count($qian) > 1) {
        $num += cn2num($qian[0]) * 1000;
        $string = $qian[1];
    }
    $bai = explode('百', $string);
    if (count($bai) > 1) {
        $num += cn2num($bai[0]) * 100;
        $string = $bai[1];
    }
    $shi = explode('十', $string);
    if (count($shi) > 1) {
        $num += cn2num($shi[0] ? $shi[0] : '一') * 10;
        $string = $shi[1] ? $shi[1] : '零';
    }
    $ling = explode('零', $string);
    if (count($ling) > 1) {
        $string = $ling[1];
    }
    $d = array(
        '一' => '1','二' => '2','三' => '3','四' => '4','五' => '5','六' => '6','七' => '7','八' => '8','九' => '9',
        '壹' => '1','贰' => '2','叁' => '3','肆' => '4','伍' => '5','陆' => '6','柒' => '7','捌' => '8','玖' => '9',
        '零' => 0, '0' => 0, 'O' => 0, 'o' => 0,
        '两' => 2
    );
    return $num + @$d[$string];
}