如何在php中比较两个时间值

$time1 = '2022-01-01 10:00:00';
$time2 = '2022-01-01 12:00:00';

if ($time1 < $time2) {
    echo "时间1早于时间2";
} elseif ($time1 > $time2) {
    echo "时间1晚于时间2";
} else {
    echo "时间1等于时间2";
}

$time1 = '2022-01-01 10:00:00';
$time2 = '2022-01-01 12:00:00';

$timestamp1 = strtotime($time1);
$timestamp2 = strtotime($time2);

if ($timestamp1 < $timestamp2) {
    echo "时间1早于时间2";
} elseif ($timestamp1 > $timestamp2) {
    echo "时间1晚于时间2";
} else {
    echo "时间1等于时间2";
}

$time1 = '2022-01-01 10:00:00';
$time2 = '2022-01-01 12:00:00';

$datetime1 = new DateTime($time1);
$datetime2 = new DateTime($time2);

if ($datetime1 < $datetime2) {
    echo "时间1早于时间2";
} elseif ($datetime1 > $datetime2) {
    echo "时间1晚于时间2";
} else {
    echo "时间1等于时间2";
}