Online PHP editor | refs for BEGKT

<?php $users = [ ['first_name' => 'Bob', 'last_name' => 'Smith'], ['first_name' => 'Steve', 'last_name' => 'Little'], ['first_name' => 'Eric', 'last_name' => 'Fielder'], ['first_name' => 'Steve', 'last_name' => 'Richardson'], ['first_name' => 'Bob', 'last_name' => 'Sanders'], ['first_name' => 'Bob', 'last_name' => 'Sanders'], ['first_name' => 'Bob', 'last_name' => 'Smith'], ]; foreach ($users as $row) { $grouped[$row['first_name']][$row['last_name'][0] ?? ''][$row['last_name']][] = $row; } $result = []; foreach ($grouped as $firstName => $leadingLetterGroup) { $leadingLetterCount = count($leadingLetterGroup); foreach ($leadingLetterGroup as $leadingLetter => $lastNameGroup) { $lastNameCount = count($lastNameGroup); foreach ($lastNameGroup as $lastName => $rows) { if (count($rows) === 1) { if ($leadingLetterCount === 1) { $username = $firstName; } elseif ($lastNameCount === 1) { $username = "$firstName $leadingLetter."; } else { $username = "$firstName $lastName"; } $result[] = $rows[0] + ['username' => $username]; } else { foreach ($rows as $i => $row) { $username = sprintf("%s %s (%d)", $firstName, $lastName, $i + 1); $result[] = $row + ['username' => $username]; } } } } } var_export($result);