[RESOLVED] How to: Return duplicate values from an array

[reeksy]

Hi

I have quite a large array. I want to search the array and return a result where the same value appears more than once within the array.

Is this possible?

Jon

[laserlight]

One way is to use [man]array_count_values/man. If you only want one result, it may be better to sort and then do a single pass for a consecutive value.

[bpat1434]

You'd have to create your own function that loops through each array item, and performs a search using [man]array_keys/man for all the keys associated with that value. If the returned array is greater than 1 element long (i.e. count($returnedArray)>1) then you know that the other numbers in that array, are all duplicates.

This seems to work well . . .

function arrayDuplicates($array, $singles=false) {
	$single = $dups = array();

foreach($array as $item) {
	$keys = array_keys($array, $item);
	if(count($keys) > 1) {
		foreach($keys as $key) {
			/*if(!in_array($key, $dups))
				$dups[] = $key;*/
			if(!in_array($array[$key], $single)) {
				$single[] = $item;
				break;
			}
			if(!in_array($array[$key], $dups))
				$dups[] = $array[$key];
		}
	}
	else if(count($keys) == 1) {
		$single[] = $item;
	}
}

natsort($dups);
natsort($single);

if($singles===false)
	return $dups;
else
	return $single;
}

$myArray = array('apples', 'oranges', 'bananas', 'hearts', 'stars', 'horseshoes', 'clovers', 'bluemoons', 'hearts', 'oranges', 'green', 'blue', 'apples', 'clovers', 'green', 'clovers', 'hearts');

echo '<pre>';
$duplicates = arrayDuplicates($myArray);
print_r($duplicates);
$singles = arrayDuplicates($myArray, true);
print_r($singles);

Offering the following results:

Array
(
    [2] => apples
    [3] => clovers
    [4] => green
    [0] => hearts
    [1] => oranges
)
Array
(
    [0] => apples
    [2] => bananas
    [9] => blue
    [7] => bluemoons
    [6] => clovers
    [8] => green
    [3] => hearts
    [5] => horseshoes
    [1] => oranges
    [4] => stars
)

[EDIT] Updated the function so it returns all array values, as what the original poster wanted.

[reeksy]

Resolved - Thank you