- implode: documentation ( source)
- array_fill: documentation ( source)
<?php
$_GET = ['row' => 5, 'column' => 4];
if (isset($_GET['row'], $_GET['column'])) {
for($i = 0; $i < $_GET['row']; $i++) {
echo implode('', array_fill(0, $_GET['column'], '*')) . PHP_EOL;
}
}