Print integers as words. (e.g. from '34' to 'thirty-four.')

numberWord.java

class numberWord {	
	//Limited to numbers under 20,000.
	//TODO punctuate properly
	public static String spellOut(int n) {
		if(n == 0) return "zero";
		String output = "";
		//This method relies on the fact Java drops the remainder of integer division
		int thousands = n / 1000;
		n -= thousands * 1000;
		int hundreds = n / 100;
		n -= hundreds * 100;
		int tens = n / 10;
		n -= tens * 10 * (n > 20 ? 1 : 0);

		if(thousands > 0) output += digits(thousands) + " thousand ";
		if(hundreds > 0) output += digits(hundreds) + " hundred ";
		if(tens >= 2) {
			String[] names = {null, null, "twenty", "thirty", "forty", "fifty",
				"sixty", "seventy", "eighty", "ninety"};
		       	output += names[tens] + " ";
		}
		if(n > 0) output += digits(n);

		return output;


	}

	private static String digits(int n) {
		String[] names = {"zero", "one", "two", "three", "four",
			"five", "six", "seven", "eight", "nine", "ten",
			"eleven", "twelve", "thirteen", "fourteen", "fifteen",
			"sixteen", "seventeen", "eighteen", "nineteen", "twenty"};
		return ((n < 20) && (n > 0)) ? names[n] : "";
	}
}