What are the potential issues that may arise when using array_combine with arrays that contain duplicate keys?

When using array_combine with arrays that contain duplicate keys, the function will only keep the last occurrence of each key-value pair. This means that data loss may occur if you have duplicate keys in your arrays. To solve this issue, you can first remove the duplicate keys from your arrays before using array_combine.

// Remove duplicate keys from arrays before using array_combine
$array1 = array(1, 2, 3);
$array2 = array('a', 'b', 'c', 'd');

// Remove duplicate keys
$array1 = array_values(array_unique($array1));
$array2 = array_values(array_unique($array2));

// Combine arrays without duplicate keys
$combinedArray = array_combine($array1, $array2);

print_r($combinedArray);