PHP格式化输出打印变量

简单版的：

print_a($result);

function print_a($a)

{
echo "<pre>";
print_r($a);
echo "</pre>";

}

dump($vars,$label,$return);

加强版本：

function dump($vars, $label = '', $return = false) {

    if (ini_get('html_errors')) {

        $content = "<pre>\n";

        if ($label != '') {

            $content .= "<strong>{$label} :</strong>\n";

        }

        $content .= htmlspecialchars(print_r($vars, true));

        $content .= "\n</pre>\n";

    } else {

        $content = $label . " :\n" . print_r($vars, true);

    }

    if ($return) { return $content; }

    echo $content;

    return null;

}