Question

Here I am to ask something weird.

I would like to ask that is there any method/logic by which we can convert an integer value to a string value containing the English words for the number?

E.g user inputs 22 and gets the output twenty two or two.

Thanks

Answer 1

Check out this code, it might be what you’re looking for. For example, inside the main method if we had:

System.out.println(convert(22));

Output:

twenty two

---

EDIT I’ve reproduced the code below, cleaning up the formatting a bit (main-method is at the bottom):

import java.text.DecimalFormat;

public class EnglishNumberToWords {

    private static final String[] tensNames = { "", " ten", " twenty",
            " thirty", " forty", " fifty", " sixty", " seventy", " eighty",
            " ninety" };

    private static final String[] numNames = { "", " one", " two", " three",
            " four", " five", " six", " seven", " eight", " nine", " ten",
            " eleven", " twelve", " thirteen", " fourteen", " fifteen",
            " sixteen", " seventeen", " eighteen", " nineteen" };

    private static String convertLessThanOneThousand(int number) {
        String soFar;

        if (number % 100 < 20) {
            soFar = numNames[number % 100];
            number /= 100;
        } else {
            soFar = numNames[number % 10];
            number /= 10;

            soFar = tensNames[number % 10] + soFar;
            number /= 10;
        }
        if (number == 0)
            return soFar;
        return numNames[number] + " hundred" + soFar;
    }

    public static String convert(long number) {
        // 0 to 999 999 999 999
        if (number == 0) {
            return "zero";
        }

        String snumber = Long.toString(number);

        // pad with "0"
        String mask = "000000000000";
        DecimalFormat df = new DecimalFormat(mask);
        snumber = df.format(number);

        // XXXnnnnnnnnn
        int billions = Integer.parseInt(snumber.substring(0, 3));
        // nnnXXXnnnnnn
        int millions = Integer.parseInt(snumber.substring(3, 6));
        // nnnnnnXXXnnn
        int hundredThousands = Integer.parseInt(snumber.substring(6, 9));
        // nnnnnnnnnXXX
        int thousands = Integer.parseInt(snumber.substring(9, 12));

        String tradBillions;
        switch (billions) {
        case 0:
            tradBillions = "";
            break;
        case 1:
            tradBillions = convertLessThanOneThousand(billions) + " billion ";
            break;
        default:
            tradBillions = convertLessThanOneThousand(billions) + " billion ";
        }
        String result = tradBillions;

        String tradMillions;
        switch (millions) {
        case 0:
            tradMillions = "";
            break;
        case 1:
            tradMillions = convertLessThanOneThousand(millions) + " million ";
            break;
        default:
            tradMillions = convertLessThanOneThousand(millions) + " million ";
        }
        result = result + tradMillions;

        String tradHundredThousands;
        switch (hundredThousands) {
        case 0:
            tradHundredThousands = "";
            break;
        case 1:
            tradHundredThousands = "one thousand ";
            break;
        default:
            tradHundredThousands = convertLessThanOneThousand(hundredThousands)
                    + " thousand ";
        }
        result = result + tradHundredThousands;

        String tradThousand;
        tradThousand = convertLessThanOneThousand(thousands);
        result = result + tradThousand;

        // remove extra spaces!
        return result.replaceAll("^\\s+", "").replaceAll("\\b\\s{2,}\\b", " ");
    }

    public static void main(String[] args) {
        System.out.println(convert(22));  // "twenty two"
    }
}