What are some alternative methods for determining the previous and next elements in an array without knowing the specific indexes?

When needing to determine the previous and next elements in an array without knowing the specific indexes, one approach is to iterate through the array and compare each element with the target element to find its position. Once the position is known, the previous and next elements can be easily accessed by referencing the elements before and after the target element. 

$target = 5;
$array = [2, 4, 5, 7, 9];

$position = array_search($target, $array);

if ($position !== false) {
    $previous = ($position > 0) ? $array[$position - 1] : null;
    $next = ($position < count($array) - 1) ? $array[$position + 1] : null;

    echo "Previous: " . $previous . "\n";
    echo "Next: " . $next;
} else {
    echo "Target element not found in the array.";
}

Keywords

array_slice array_keys array_search array_values array_shift

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