php - How to determine the first and last iteration in a foreach loop?

Question

The question is simple. I have a foreach loop in my code:

foreach($array as $element) {
    //code
}

In this loop, I want to react differently when we are in first or last iteration.

How to do this?

Answer 1

If you prefer a solution that does not require the initialization of the counter outside the loop, then you can compare the current iteration key against the function that tells you the last / first key of the array.

PHP 7.3 and newer:

foreach ($array as $key => $element) {
    if ($key === array_key_first($array)) {
        echo 'FIRST ELEMENT!';
    }

    if ($key === array_key_last($array)) {
        echo 'LAST ELEMENT!';
    }
}

PHP 7.2 and older:

foreach ($array as $key => $element) {
    reset($array);
    if ($key === key($array)) {
        echo 'FIRST ELEMENT!';
    }

    end($array);
    if ($key === key($array)) {
        echo 'LAST ELEMENT!';
    }
}