How to get previous and next array value in php?

So I am using a RapidAPI's API where I am getting this below array after json_encode() it -

Array
(
    [00:00:00] => Array
        (
            [name] => Arr Name 1
            [other-details] => Arr Desscription 1
            [type] => Arr Type 1
        )

    [00:30:00] => Array
        (
            [name] => Arr Name 2
            [other-details] => Arr Desscription 2
            [type] => Arr Type 2
        )
)

Now that you have seen the structure I am getting from now on please notice that I am getting only the starting time I.e [00:00:00] and not the ending time i.e it should have been [00:30:00] the end time.

But using

foreach ($arr as $key => $value) { 
}

I am getting

[00:00:00]
[00:30:00]

respectively as you can expect in foreach I have tried using foreach inside foreach using array_slice but failed.

So what I want is

Start Time - End Time
[00:00:00] [00:30:00]
[00:30:00] .....

Solution

You might take and loop the keys from the array using array_keys.

In the loop, print the starting time, and only print the ending time if it exist by checking if the key for the next value in the array exists.

$a = [
    '00:00:00' => [
        'name' => 'Arr Name 1',
        'other-details' => 'Arr Desscription 1',
        'type' => 'Arr Type 1'
    ],
    '00:00:30' => [
        'name' => 'Arr Name 2',
        'other-details' => 'Arr Desscription 2',
        'type' => 'Arr Type 2'
    ],
    '00:01:00' => [
        'name' => 'Arr Name 3',
        'other-details' => 'Arr Desscription 3',
        'type' => 'Arr Type 3'
    ],
    '00:01:30' => [
        'name' => 'Arr Name 4',
        'other-details' => 'Arr Desscription 4',
        'type' => 'Arr Type 4'
    ]
];

$keys = array_keys($a);
for ($i = 0; $i < count($keys); $i++) {
    $result = $keys[$i];
    if (array_key_exists($i+1, $keys)) {
        $result .= " " . $keys[$i + 1];
    }
    echo $result . PHP_EOL;
}

Output

00:00:00 00:00:30
00:00:30 00:01:00
00:01:00 00:01:30
00:01:30

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