Convert from any base to any base in PHP

base_convert.php

<?php

function convertBases($number, $from_digits, $to_digits)
{
	$from_digits = str_split($from_digits, 1);
	$to_digits = str_split($to_digits, 1);
	$number = str_split($number, 1);

	$number_dec = "0";
	$ord = 0;

	while(count($number))
	{
		$digit 			= array_search(array_pop($number), $from_digits);
		$digit_value 	= bcmul($digit, bcpow(count($from_digits), $ord));
		$number_dec 	= bcadd($number_dec, $digit_value);
		$ord++;
	}
	$result_digits = array();

	do {
		$result_digits[] = bcmod($number_dec, count($to_digits));
		$number_dec = bcdiv($number_dec, count($to_digits), 0);
	} while($number_dec !== "0");


	$result = "";
	while(count($result_digits))
	{
		$result .= $to_digits[array_pop($result_digits)];
	}
	
	return $result;
}

echo convertBases( "FF", "0123456789ABCDEF", "0123456789" ), "\n";
// Prints 255
echo convertBases( "255", "0123456789", "0123456789ABCDEF" ), "\n";
// Prints FF