Create a Table from pairs of array

[doc1355]

I have an array as below: 

Array
(
    [0] => Array
        (
            [u1] => 6
            [u2] => 4
        )

    [1] => Array
        (
            [u1] => 6
            [u2] => 3
        )

    [2] => Array
        (
            [u1] => 3
            [u2] => 4
        )

    [3] => Array
        (
            [u1] => 3
            [u2] => 11
        )

    [4] => Array
        (
            [u1] => 3
            [u2] => 11
        )

    [5] => Array
        (
            [u1] => 3
            [u2] => 4
        )

    [6] => Array
        (
            [u1] => 4
            [u2] => 11
        )

    [7] => Array
        (
            [u1] => 4
            [u2] => 11
        )

    [8] => Array
        (
            [u1] => 6
            [u2] => 3
        )

    [9] => Array
        (
            [u1] => 6
            [u2] => 4
        )

    [10] => Array
        (
            [u1] => 6
            [u2] => 11
        )

    [11] => Array
        (
            [u1] => 6
            [u2] => 11
        )

)

What I'm trying to achieve is to create a table as below: 

6:  4   3  3  4  11   11

4:  6   3  3  11  11   6

3:  6   4  11  11  4   6 

11: 3   3   4   4  6   6 

 

Here is what is happening: 

It shows the first value of u1 (6) , then searches all the other arrays, if that value (6) exists, it shows the other value one at a time ( 4-3-3-4-11-11). Then starts new row, looks up the next value (which is not same as the first value and goes through the same process, until we have one row for all the unique numbers in the array, then stops. 

I'm not sure how I can setup my loop to do this and I appreciate any helps that anyone could offer. 

 

Thank you. 

 

[Barand]

Create an intermediate array which restructures your data

foreach ($array as $a) {
    if (!isset($new[$a['u1']])) {
        $new[$a['u1']] = [];
    }
    $new[$a['u1']][] = $a['u2'];
}

which gives $new array ...

Array
(
    [6] => Array
        (
            [0] => 4
            [1] => 3
            [2] => 3
            [3] => 4
            [4] => 11
            [5] => 11
        )

    [3] => Array
        (
            [0] => 4
            [1] => 11
            [2] => 11
            [3] => 4
        )

    [4] => Array
        (
            [0] => 11
            [1] => 11
        )

)

Now it's simple to loop through outputting the rows and columns.

[doc1355]

Thank you so much for your quick reply. This is a great help. 

By using the loop with the $new variable I can show half of the table (blue) only and not the other half (red). I know this is duplicate of the blue data . How can I show the second half (red) in my loop to make it a full table?

6:  4   3  3  4  11   11

4:  6   3  3  11  11   6

3:  6   4  11  11  4   6 

11: 3   3   4   4  6   6 

Edited August 31, 2021 by doc1355

[Barand]

Rinse and repeat - exchanging u1 and u2

$new = [];
foreach ($array as $a) {
    if (!isset($new[$a['u1']])) {
        $new[$a['u1']] = [];
    }
    $new[$a['u1']][] = $a['u2'];
    //repeat exchanging u1 and u2
    if (!isset($new[$a['u2']])) {
        $new[$a['u2']] = [];
    }
    $new[$a['u2']][] = $a['u1'];
}
//
//  Output $new array
//
echo '<pre>';
foreach ($new as $u1 => $u2s) {
    printf('<br><b>%4d</b> | ', $u1);
    foreach ($u2s as $u) {
        printf('%4d &vellip;', $u);
    }
}  

[doc1355]

Brilliant. This worked like a charm. 

Thank you so much.