php - Checking during array iteration, if the current element is the last element

Question

Please help me to translate this pseudo-code to real php code:

 foreach ($arr as $k => $v)
    if ( THIS IS NOT THE LAST ELEMENT IN THE ARRAY)
        doSomething();

Edit: the array may have numerical or string keys

Answer 1

you can use PHP's end()

$array = array('a' => 1,'b' => 2,'c' => 3);
$lastElement = end($array);
foreach($array as $k => $v) {
    echo $v . '<br/>';
    if($v == $lastElement) {
         // 'you can do something here as this condition states it just entered last element of an array'; 
    }
}

Update1

as pointed out by @Mijoja the above could will have problem if you have same value multiple times in array. below is the fix for it.

$array = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 2);
//point to end of the array
end($array);
//fetch key of the last element of the array.
$lastElementKey = key($array);
//iterate the array
foreach($array as $k => $v) {
    if($k == $lastElementKey) {
        //during array iteration this condition states the last element.
    }
}

Update2

I found solution by @onteria_ to be better then what i have answered since it does not modify arrays internal pointer, i am updating the answer to match his answer.

$array = array('a' => 1, 'b' => 2, 'c' => 3, 'd' => 2);
// Get array keys
$arrayKeys = array_keys($array);
// Fetch last array key
$lastArrayKey = array_pop($arrayKeys);
//iterate array
foreach($array as $k => $v) {
    if($k == $lastArrayKey) {
        //during array iteration this condition states the last element.
    }
}

Thank you @onteria_

Update3

As pointed by @CGundlach PHP 7.3 introduced array_key_last which seems much better option if you are using PHP >= 7.3

$array = array('a' => 1,'b' => 2,'c' => 3);
$lastKey = array_key_last($array);
foreach($array as $k => $v) {
    echo $v . '<br/>';
    if($k == $lastKey) {
         // 'you can do something here as this condition states it just entered last element of an array'; 
    }
}