如何使用PHP将一小时缩短到最近的2小时间隔？

Question

I have 4 time values:

$times = array('16:04:12', '16:57:54', '17:59:59', '18:00:00');

I would like to divide the 24 hour time to 2 hour intervals so I will have 12 hours, like: 0:00:01-1:59:59, 2:00:00-3:59:59, 4:00:00-5:59:59, etc.

What I want to do is place these values into those intervals. So the final result should be:

$result = array(
    '16:00:00-17:59:59' => array('16:04:12', '16:57:54', '17:59:59'),
    '18:00:00-19:59:59' => array('18:00:00')
);

I have tried to create an array with the intervals and then loop through it checking if one is bigger than the other, but it did not work as intended.

How is it possible to put the hours into these 2 hour intervals?

Answer 1

I think in your case you should just compare hours
and don't write some sophisticated and unreadable code.
For example:

<?php

$times = array('16:04:12', '16:57:54', '17:59:59', '18:00:00');
foreach ($times as $t) {
    // extract hour from string
    $h = substr($t, 0, 2);
    if ($h%2 === 0) {
        $key = sprintf('%02d:00:00-%02d:59:59', $h, $h+2);
    } else {
        $key = sprintf('%02d:00:00-%02d:59:59', $h-1, $h+1);
    }
    // this key will resolve all values
    $r[$key][] = $t;
}
var_export($r);

This will prints:

array (
  '16:00:00-18:59:59' => 
  array (
    0 => '16:04:12',
    1 => '16:57:54',
    2 => '17:59:59',
  ),
  '18:00:00-20:59:59' => 
  array (
    0 => '18:00:00',
  ),
)

Hope it will help you, because this code looks very understandable...