仅回显array_count_values结果php的重复值

Question

After both myself and a friend searching for hours upon end, and trying numerous things we are unable to find out how to echo only the duplicate values of array_count_values result. I will break it down:

We have numerous select boxes, which build the array when sent via GET, for example:

    <div class="form-group col-sm-2 mb-sm">
            <select name="select[]" class="form-control">
                <option value="" disabled="" selected="">Select</option>
                <option value="optionOne">Option 1</option>
                <option value="optionTwo">Option 2</option>
            </select>
        </div>
        <div class="form-group col-sm-2 mb-sm">
            <select name="select[]" class="form-control">
                <option value="" disabled="" selected="">Select</option>
                <option value="optionOne">Option 1</option>
                <option value="optionTwo">Option 2</option>
            </select>
        </div>
        <div class="form-group col-sm-2 mb-sm">
            <select name="select[]" class="form-control">
                <option value="" disabled="" selected="">Select</option>
                <option value="optionOne">Option 1</option>
                <option value="optionTwo">Option 2</option>
            </select>
        </div>

We are then doing the following:

if (max(array_count_values($_GET['select'])) == 2) {
   $twoSelected = '2 of the selections are the same, which were (DUPLICATE SELECTION HERE)';
}

We have tried a foreach loop, but can't seem to get it to work.

Any help will be very much appreciated.

Kind Regards

Answer 1

Try this one

$array = array("test", "hello", "test", "world", "hello");

$duplicatedValuesArray = array_keys(array_filter(array_count_values($array), function($v) {
    return $v > 1;
}));

echo implode(', ',$duplicatedValuesArray);