php 常用工具函数

返回时间戳差值部分，年、月、日

function get_date_diff($startstamp, $endstamp, $return = 'm')
{
    $y = date('Y', $endstamp) - date('Y', $startstamp);
    $m = date('m', $endstamp) - date('m', $startstamp);
    
    switch ($return) {
        case 'y':
            if ($y <= 1) {
                $y = $m / 12;
            }
            $string = $y;
            break;
        case 'm':
            $string = $y * 12 + $m;
            break;
        case 'd':
            $string = ($endstamp - $startstamp) / 86400;
            break;
    }
    return $string;
}