How to implement such a thing (in the picture)?

Question

Delphi

What is the component highlighted in red? Should change the number of table rows when changing the value.

Answer 1

A couple of TEdit and TUpDown.

Answer 2

TSpinEdit

Answer 3

<?php
$x = [
    'А' => '1',
    'B' => '2',
    'C' => '3',
    'D' => '4'
];
$y['A'] = array_shift($x);
$y['B'] = implode('#', $x);
?>

For a more specific answer, specify what exactly you are changing there.
Well, my method changes the x array, if you need an unchanged one - it is desirable to redo the code a little

Answer 4

$x = [
    'А' => '1',
    'B' => '2',
    'C' => '3',
    'D' => '4'
];

function magic($x)
{
    $k = array_keys($x);
    $v = array_shift($x);
    
    return [$k[0] => $v, $k[1] => implode('#', $x)];
}

print_r(magic($x));