Detect if array of objects within an object has duplicate names

Question

I'm looking for a smart way to find out if my array of objects within an object has multiple name values or not to do a validation since it's only allowed to have one array name per inner array:

$elements = [];

$elements[18][20] = [
    [
        'name'  => 'Color',
        'value' => 'Red'
    ],
    [
        'name'  => 'Color',
        'value' => 'Green'
    ],
    [
        'name'  => 'Size',
        'value' => 'S'
    ]
];
$elements[18][21] = [
    [
        'name'  => 'Size',
        'value' => 'S'
    ],
    [
        'name'  => 'Length',
        'value' => '20'
    ],
];

error_log( print_r( $elements, true ) );

So the object 20 for example is invalid because it has 2 colors with the same value. At the end I was hoping to get a result array containing 1 duplicate name. This way I can output them like: "You have at least one duplicate name: Color".

My first idea was to loop over the array and do a second loop. This way it was possible to receive the inner arrays containing the stuff. Now I was able to add every name to another array. After this I was able to use count() and array_intersect() to receive a value of x which showed me if there are duplicates or not.

Now I had a count, but not the actual value to display. Before I use a semi-good solution, I was hoping to get any ideas here how I can make it better!

Manuel Guzman · Accepted Answer · 2022-03-06 00:28:05Z

1

This loop will generate your expected output:

foreach($elements[18] as $index => $element){
    //Get all the elements' names
    $column_key = array_column($element, 'name');
    //Get the count of all keys in the array
    $counted_values = array_count_values($column_key);
    //Check if count is > 1
    $filtered_array = array_filter($counted_values, fn($i) => $i > 1);
    //If the filter is not empty, show the error
    if(!empty($filtered_array)){
        //get the key name
        $repeated_key = array_key_first($filtered_array);
        echo "You have at least one duplicate name: {$repeated_key} at index {$index}";
        break;
    }
}

It relies in the array_count_values function.

answered Mar 6, 2022 at 0:28

Manuel Guzman

6436 silver badges15 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Mr. Jo Over a year ago

Thank you for your help. I actually used your logic to complete my function. Since I want to print out every duplicate, I've saved all $filtered_arrays to another array and returned it in case there is an error. This way I was able to get all the wrong values.

Collectives™ on Stack Overflow

Detect if array of objects within an object has duplicate names

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related