PHP
Remove Duplicates and Re-index a Numeric Array
Learn how to efficiently remove duplicate values from a PHP numeric array and re-index it to ensure sequential keys after removal, improving array consistency.
<?php
$data = [1, 2, 2, 3, 4, 4, 5, 1];
// Remove duplicate values
$uniqueValues = array_unique($data);
// Re-index the array to have sequential keys starting from 0
$reindexedArray = array_values($uniqueValues);
print_r($reindexedArray);
// Output:
// Array
// (
// [0] => 1
// [1] => 2
// [2] => 3
// [3] => 4
// [4] => 5
// )
?>
How it works: This snippet demonstrates a common pattern for cleaning up PHP arrays. `array_unique()` removes all duplicate values, but it preserves the original keys. To get a clean, sequentially indexed array (0, 1, 2...), `array_values()` is used immediately afterward to re-index the array. This is particularly useful when preparing data for display or further processing where non-sequential keys might cause issues.