Numbers To Words

This algorithm converts decimal numbers to its English word representation.

• C#
• VB.Net
• C
• C++
• PHP

									function NumbersToWords($num)
{
	$words = "";
	$singles = array("zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine");
	$teens = array("ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen");
	$tens = array("", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninty");
	$powers = array("", "thousand", "million", "billion", "trillion", "quadrillion", "quintillion");

	if ($num >= 1000)
	{
		$powersLength = count($powers);
		for ($i = $powersLength - 1; $i >= 0; $i--)
		{
			$power = pow(1000, $i);
			$count = floor(($num - fmod($num, $power)) / $power);
			
			if ($num > $power)
			{
				$words .= NumbersToWords($count) . " " . $powers[$i];
				$num -= ($count * $power);
			}
		}
	}

	if ($num >= 100)
	{
		$count = floor(($num - ($num % 100)) / 100);
		$words .= NumbersToWords($count) . " hundred";
		$num -= ($count * 100);
	}

	if ($num >= 20 && $num < 100)
	{
		$count = floor(($num - ($num % 10)) / 10);
		$words .= " " . $tens[$count];
		$num -= ($count * 10);
	}

	if ($num >= 10 && $num < 20)
	{
		$words .= " " . $teens[$num - 10];
		$num = 0;
	}

	if ($num > 0 && $num < 10)
	{
		$words .= " " . $singles[$num];
	}

	return $words;
}
								

Example

									$data = 5478775544879599;
$value = NumbersToWords($data);
								

Output

									five quadrillion four hundred seventy eight trillion seven hundred seventy five billion five hundred forty four million eight hundred seventy nine thousand five hundred ninty nine