Java Algorithms Convert number to English words example 3

import java.util.Scanner;

public class Main {
   String string;//from  w  w w  .j ava 2  s  .c om
   String st1[] = { "", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", };
   String st2[] = { "hundred", "thousand", "lakh", "crore" };
   String st3[] = { "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen",
         "ninteen", };
   String st4[] = { "twenty", "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninety" };

   public String convert(int number) {
      int n = 1;
      int word;
      string = "";
      while (number != 0) {
         switch (n) {
         case 1:
            word = number % 100;
            pass(word);
            if (number > 100 && number % 100 != 0) {
               show("and ");
               // System.out.print("ankit");
            }
            number /= 100;
            break;
         case 2:
            word = number % 10;
            if (word != 0) {
               show(" ");
               show(st2[0]);
               show(" ");
               pass(word);
            }
            number /= 10;
            break;
         case 3:
            word = number % 100;
            if (word != 0) {
               show(" ");
               show(st2[1]);
               show(" ");
               pass(word);
            }
            number /= 100;
            break;
         case 4:
            word = number % 100;
            if (word != 0) {
               show(" ");
               show(st2[2]);
               show(" ");
               pass(word);
            }
            number /= 100;
            break;
         case 5:
            word = number % 100;
            if (word != 0) {
               show(" ");
               show(st2[3]);
               show(" ");
               pass(word);
            }
            number /= 100;
            break;
         }
         n++;
      }
      return string;
   }

   public void pass(int number) {
      int word, q;
      if (number < 10) {
         show(st1[number]);
      }
      if (number > 9 && number < 20) {
         show(st3[number - 10]);
      }
      if (number > 19) {
         word = number % 10;
         if (word == 0) {
            q = number / 10;
            show(st4[q - 2]);
         } else {
            q = number / 10;
            show(st1[word]);
            show(" ");
            show(st4[q - 2]);
         }
      }
   }

   public void show(String s) {
      String st;
      st = string;
      string = s;
      string += st;
   }

   public static void main(String[] args) {
      Main w = new Main();
      Scanner input = new Scanner(System.in);
      System.out.print("Enter Number: ");
      int num = input.nextInt();
      String inwords = w.convert(num);
      System.out.println(inwords);
   }
}