PHP Array Exercises : Identify the email addresses which are not unique

PHP Array: Exercise-41 with Solution

Write a PHP program to identify the email addresses which are not unique.

Sample Solution:

PHP Code:

function array_not_unique($my_array) {
    $same = array();
    reset ($my_array);

    $old_key    = NULL;
    $old_value    = NULL;
    foreach ($my_array as $key => $value) {
        if ($value === NULL) { continue; }
        if ($old_value == $value) {
            $same[$old_key]    = $old_value;
            $same[$key]        = $value;
        $old_value    = $value;
        $old_key    = $key;
return $same;

$test_array = array();
$test_array[1]    = '[email protected]';
$test_array[2]    = '[email protected]';
$test_array[3]    = '[email protected]';
$test_array[4]    = '[email protected]';


Sample Output:

    [1] => [email protected]                                          
    [3] => [email protected]                                          


Flowchart: PHP - Identify the email addresses which are not unique

PHP Code Editor:

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