// 在使用var_dump/print_r时   打印出来的数组 都是一行显示的， 看起来不方便 function dump($vars, $label = '', $return = false) {    if (ini_get('html_errors')) {        $content = "
\n";        if ($label != '') {            $content .= "{
   $label} :\n";        }        $content .= htmlspecialchars(print_r($vars, true));        $content .= "\n
\n";    } else {        $content = $label . " :\n" . print_r($vars, true);    }    if ($return) { return $content; }    echo $content;    return null;}