I am converting this javascript code into PHP, but it seems not working

const printNumberStarMatrix = function (row, col) {

    for (let i = 1; i <= row; ++i) {
        let strToPrint = "";
        for (let j = col - i; j >= 1; --j) {
            strToPrint = j + strToPrint;
        }
        while (strToPrint.length < col) {
            strToPrint += "*";
        }
        console.log(strToPrint);
    }
}

<?php
$printNumberStarMatrix = function ($row, $col) {
	for ($i = 1; $i <= $row; ++$i) {
		$strToPrint = "";
			for ($j = $col - $i; $j >= 1; --$j) {
				$strToPrint = $j + $strToPrint;
			}
	}
	while ($strToPrint < $col) {
		$strToPrint += "*";
		}
echo $strToPrint;
	};
$printNumberStarMatrix(5, 6);
?>