How to detect duplicate values in PHP array?

I am working with a one dimensional array in PHP. I would like to detect the presence of duplicate values, then count the number of duplicate values and out put the results. For example, given the following array:

$array = array('apple', 'orange', 'pear', 'banana', 'apple',
   'pear', 'kiwi', 'kiwi', 'kiwi');

I would like to print:

apple (2)
orange
pear (2)
banana
kiwi (3)

Any advice on how to approach this problem?

Thanks.

Mike


You can use array_count_values function

$array = array('apple', 'orange', 'pear', 'banana', 'apple',
'pear', 'kiwi', 'kiwi', 'kiwi');

print_r(array_count_values($array));

will output

Array
(
   [apple] => 2
   [orange] => 1
   [pear] => 2
   etc...
)

if(count(array_unique($array))<count($array))
{
    // Array has duplicates
}
else
{
    // Array does not have duplicates
}

function array_not_unique( $a = array() )
{
  return array_diff_key( $a , array_unique( $a ) );
}

You could try turning that array into a associative array with the fruits as keys and the number of occurrences as values. Bit long-winded, but it looks like:

$array = array('apple', 'orange', 'pear', 'banana', 'apple',
   'pear', 'kiwi', 'kiwi', 'kiwi');
$new_array = array();
foreach ($array as $key => $value) {
    if(isset($new_array[$value]))
        $new_array[$value] += 1;
    else
        $new_array[$value] = 1;
}
foreach ($new_array as $fruit => $n) {
    echo $fruit;
    if($n > 1)
        echo "($n)";
    echo "<br />";
}