How do I find duplicates in a PHP array?

Question

Is there anyway to find duplicates in array values? like:-

$cars = array("Volvo", "BMW", "Toyota", "BMW", "Toyota");

As BMW and Toyota occurs twice output would be BMW and Toyota i know about array_search() but in that you have to provide what you want to search.. i can match array value with respect to key but size of array can vary, It would be great if anyone help me out.

What do you mean "match values"? Are you asking "How do I find duplicates in a PHP array?" — tadman, May 05 '18 at 17:49
Possible duplicate of [How to detect duplicate values in PHP array?](https://stackoverflow.com/questions/1170807/how-to-detect-duplicate-values-in-php-array) — Pradeep, May 05 '18 at 17:57
Lots of ways to end up with an array of unique items... what exactly are you trying to do? — ivanivan, May 05 '18 at 18:04

score 8 · Accepted Answer · answered May 05 '18 at 17:53

One option is using array_count_values() and include only array elements with more than one values.

$cars = array("Volvo", "BMW", "Toyota", "BMW", "Toyota");

foreach( array_count_values($cars) as $key => $val ) {
    if ( $val > 1 ) $result[] = $key;   //Push the key to the array sice the value is more than 1
}

echo "<pre>";
print_r( $result );
echo "</pre>";

This will result to:

Array
(
    [0] => BMW
    [1] => Toyota
)

Doc: array_count_values()

score 0 · Answer 2 · answered May 05 '18 at 18:03

0

You can do like this

function array_match_dump($array){
   return array_unique(array_diff_assoc($array,array_unique($array)));
}

answered May 05 '18 at 18:03

Hiruna De Alwis

54
4

How do I find duplicates in a PHP array?

2 Answers2