Cómo convertir números a palabras en Java

Actualmente tenemos un mecanismo rudimentario para convertir números en palabras (por ejemplo, usando algunas matrices estáticas) y, según el tamaño del número, lo traducimos a un texto en inglés. Pero nos encontramos con problemas de números que son enormes.

10183 = Ten thousand one hundred eighty three
90 = Ninety
5888 = Five thousand eight hundred eighty eight

¿Hay una función fácil de usar en alguna de las bibliotecas matemáticas que pueda usar para este propósito?

ICU4J contiene un buen soporte para deletrear números. Los archivos con las “reglas” se pueden editar fácilmente, y no hay problema para agregar otros idiomas (lo hicimos, por ejemplo, para polaco y ruso).

Creo que esta solución no es la mejor, ya que solo funciona para intpero creo que es genial para un principiante.

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

    public static final String[] tens = {
            "",        // 0
            "",        // 1
            "twenty",  // 2
            "thirty",  // 3
            "forty",   // 4
            "fifty",   // 5
            "sixty",   // 6
            "seventy", // 7
            "eighty",  // 8
            "ninety"   // 9
    };

    public static String convert(final int n) {
        if (n < 0) {
            return "minus " + convert(-n);
        }

        if (n < 20) {
            return units[n];
        }

        if (n < 100) {
            return tens[n / 10] + ((n % 10 != 0) ? " " : "") + units[n % 10];
        }

        if (n < 1000) {
            return units[n / 100] + " hundred" + ((n % 100 != 0) ? " " : "") + convert(n % 100);
        }

        if (n < 1000000) {
            return convert(n / 1000) + " thousand" + ((n % 1000 != 0) ? " " : "") + convert(n % 1000);
        }

        if (n < 1000000000) {
            return convert(n / 1000000) + " million" + ((n % 1000000 != 0) ? " " : "") + convert(n % 1000000);
        }

        return convert(n / 1000000000) + " billion"  + ((n % 1000000000 != 0) ? " " : "") + convert(n % 1000000000);
    }

    public static void main(final String[] args) {
        final Random generator = new Random();

        int n;
        for (int i = 0; i < 20; i++) {
            n = generator.nextInt(Integer.MAX_VALUE);

            System.out.printf("%10d = '%s'%n", n, convert(n));
        }

        n = 1000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 2000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 10000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 11000;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = 999999999;
        System.out.printf("%10d = '%s'%n", n, convert(n));

        n = Integer.MAX_VALUE;
        System.out.printf("%10d = '%s'%n", n, convert(n));
    }
}

La prueba crea 20 números aleatorios hasta Integer.MAX_VALUE y que algunos que saben que son problemáticos, por 0, 10, etc. Salida:

   5599908 = 'five million five hundred ninety nine thousand nine hundred eight'
 192603486 = 'one hundred ninety two million six hundred three thousand four hundred eighty six'
1392431868 = 'one billion three hundred ninety two million four hundred thirty one thousand eight hundred sixty eight'
1023787010 = 'one billion twenty three million seven hundred eighty seven thousand ten'
1364396236 = 'one billion three hundred sixty four million three hundred ninety six thousand two hundred thirty six'
1511255671 = 'one billion five hundred eleven million two hundred fifty five thousand six hundred seventy one'
 225955221 = 'two hundred twenty five million nine hundred fifty five thousand two hundred twenty one'
1890141052 = 'one billion eight hundred ninety million one hundred forty one thousand fifty two'
 261839422 = 'two hundred sixty one million eight hundred thirty nine thousand four hundred twenty two'
 728428650 = 'seven hundred twenty eight million four hundred twenty eight thousand six hundred fifty'
 860607319 = 'eight hundred sixty million six hundred seven thousand three hundred nineteen'
 719753587 = 'seven hundred nineteen million seven hundred fifty three thousand five hundred eighty seven'
2063829124 = 'two billion sixty three million eight hundred twenty nine thousand one hundred twenty four'
1081010996 = 'one billion eighty one million ten thousand nine hundred ninety six'
 999215799 = 'nine hundred ninety nine million two hundred fifteen thousand seven hundred ninety nine'
2105226236 = 'two billion one hundred five million two hundred twenty six thousand two hundred thirty six'
1431882940 = 'one billion four hundred thirty one million eight hundred eighty two thousand nine hundred forty'
1991707241 = 'one billion nine hundred ninety one million seven hundred seven thousand two hundred forty one'
1088301563 = 'one billion eighty eight million three hundred one thousand five hundred sixty three'
 964601609 = 'nine hundred sixty four million six hundred one thousand six hundred nine'
      1000 = 'one thousand'
      2000 = 'two thousand'
     10000 = 'ten thousand'
     11000 = 'eleven thousand'
 999999999 = 'nine hundred ninety nine million nine hundred ninety nine thousand nine hundred ninety nine'
2147483647 = 'two billion one hundred forty seven million four hundred eighty three thousand six hundred forty seven'

Espero eso ayude 🙂

package it.tommasoresti.facebook;

class NumbersToWords {

    private static final String ZERO = "zero";
    private static String[] oneToNine = {
            "one", "two", "three", "four", "five", "six", "seven", "eight", "nine"
    };

    private static String[] tenToNinteen = {
            "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"
    };

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

    public static String solution(int number) {
        if(number == 0)
            return ZERO;

        return generate(number).trim();
    }

    public static String generate(int number) {
        if(number >= 1000000000) {
            return generate(number / 1000000000) + " billion " + generate(number % 1000000000);
        }
        else if(number >= 1000000) {
            return generate(number / 1000000) + " million " + generate(number % 1000000);
        }
        else if(number >= 1000) {
            return generate(number / 1000) + " thousand " + generate(number % 1000);
        }
        else if(number >= 100) {
            return generate(number / 100) + " hundred " + generate(number % 100);
        }

        return generate1To99(number);
    }

    private static String generate1To99(int number) {
        if (number == 0)
            return "";

        if (number <= 9)
            return oneToNine[number - 1];
        else if (number <= 19)
            return tenToNinteen[number % 10];
        else {
            return dozens[number / 10 - 1] + " " + generate1To99(number % 10);
        }
    }
}

Prueba

@Test
public void given_a_complex_number() throws Exception {
    assertThat(solution(1234567890),
        is("one billion two hundred thirty four million five hundred sixty seven thousand eight hundred ninety"));
}

/**

This Program will display the given number in words from 0 to 999999999

@author Manoj Kumar Dunna

Mail Id : [email protected]

**/  


import java.util.Scanner;

class NumberToString
{

    public enum hundreds {OneHundred, TwoHundred, ThreeHundred, FourHundred, FiveHundred, SixHundred, SevenHundred, EightHundred, NineHundred}
    public enum tens {Twenty, Thirty, Forty, Fifty, Sixty, Seventy, Eighty, Ninety}
    public enum ones {One, Two, Three, Four, Five, Six, Seven, Eight, Nine}
    public enum denom {Thousand, Lakhs, Crores}
    public enum splNums { Ten, Eleven, Twelve, Thirteen, Fourteen, Fifteen, Sixteen, Seventeen, Eighteen, Nineteen}
    public static String text = "";

    public static void main(String[] args) 
    {
        System.out.println("Enter Number to convert into words");
        Scanner sc = new Scanner(System.in);
        long num = sc.nextInt();
        int rem = 0;
        int i = 0;
        while(num > 0)
        {
            if(i == 0){
                rem = (int) (num % 1000);
                printText(rem);
                num = num / 1000;
                i++;
            }
            else if(num > 0)
            {
                rem = (int) (num % 100);
                if(rem > 0)
                    text = denom.values()[i - 1]+ " " + text;
                printText(rem);
                num = num / 100;
                i++;
            }
        }
        if(i > 0)
            System.out.println(text);
        else
            System.out.println("Zero");
    }

    public static void printText(int num)
    {
        if(!(num > 9 && num < 19))
        {
            if(num % 10 > 0)
                getOnes(num % 10);

            num = num / 10;
            if(num % 10 > 0)
                getTens(num % 10);

            num = num / 10;
            if(num > 0)
                getHundreds(num);
        }
        else
        {
            getSplNums(num % 10);
        }
    }

    public static void getSplNums(int num)
    {
        text = splNums.values()[num]+ " " + text;
    }

    public static void getHundreds(int num)
    {
        text = hundreds.values()[num - 1]+ " " + text;
    }

    public static void getTens(int num)
    {
        text = tens.values()[num - 2]+ " " + text;
    }

    public static void getOnes(int num)
    {
        text = ones.values()[num - 1]+ " " + text;
    }
}