BaseToDecimal

If n is a positive integer in Java, n % 10 is its rightmost digit and n / 10 is the integer obtained by dropping the rightmost digit from n. Using these facts, write a recursive method called displayDigits that displays the digits of an integer n in decimal. For example, the integer number 345 should be displayed as a String "3 4 5"; where the negative integer number -345 should be displayed as a String "-3 4 5". Note the spaces between the digits.

Now observe that you can display n in any base between 2 and 9 by replacing 10 with the new base. Write displayDigits2to9Base method that is a revised version of yours displayDigits method, to accommodate a given base. Please note that the modified method will essentially convert a decimal number into its equivalent in the given base. For example, 10 in base 8 will be displayed as a String "1 2"; 5 in base 2 will be displayed as a String "1 0 1", and so on.

Test your methods with the driver provided in main.

public class BaseToDecimal { /** Task: Recursively displays any decimal integer.  * For example 123 would be displayed as 1 2 3  * -123 would be displayed as - 1 2 3  * @param n an integer to be displayed */  public static String displayDigits(int n) { // TODO Project #1a  return "???"; // this is a stub // IMPLEMENT THE METHOD // STEP#1 Base case: We have a single positive digit // STEP#2 recursive case: negative number // STEP#3 recursive case: positive number with more than one digit } // end displayDigits /** Task: Recursively displays any integer in a given base.  * For example 5 in base 2 would be displayed as 1 0 1  * 345 in base 8 would be displayed as 5 3 1  * @param n an integer to be displayed  * @param base an integer that is the new base of n, where 2 <= base < 10  **/  public static String displayDigits2to9Base(int n, int base) { // TODO Project #1b  return "???"; // this is a stub // IMPLEMENT THE METHOD } // end displayDigits public static void main(String args[]) { BaseToDecimal tester = new BaseToDecimal(); tester.testValues(); } public void testValues() { System.out.println("TESTING TO SEE IF IT GETS THE CORRECT RESULTS IN BASE 10"); BaseToDecimal rd = new BaseToDecimal(); int number = 5; String result; System.out.println("Trying a 1 digit integer in base 10"); result = rd.displayDigits(number); if(result.equals("5")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of 5"); number = -5; System.out.println("Trying a 1 digit negative integer in base 10"); result = rd.displayDigits(number); if(result.equals("- 5")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of - 5"); number = 345; System.out.println("Trying a 3 digit positive integer in base 10"); result = rd.displayDigits(number); if(result.equals("3 4 5")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of 3 4 5"); number = -345; System.out.println("Trying a 3 digit negative integer in base 10"); result = rd.displayDigits(number); if(result.equals("- 3 4 5")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of - 3 4 5"); System.out.println(); System.out.println("TESTING TO SEE IF IT GETS THE CORRECT RESULTS IN BASE 8"); number = 5; System.out.println("Trying a 1 digit integer in base 8"); result = rd.displayDigits2to9Base(number, 8); if(result.equals("5")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of 5"); number = -5; System.out.println("Trying a 1 digit negative integer in base 8"); result = rd.displayDigits2to9Base(number, 8); if(result.equals("- 5")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of - 5"); number = 345; System.out.println("Trying a 3 digit positive integer in base 8"); result = rd.displayDigits2to9Base(number, 8); if(result.equals("5 3 1")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of 5 3 1"); number = -345; System.out.println("Trying a 3 digit negative integer in base 8"); result = rd.displayDigits2to9Base(number, 8); if(result.equals("- 5 3 1")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of - 5 3 1"); System.out.println(); System.out.println("TESTING TO SEE IF IT GETS THE CORRECT RESULTS IN BASE 2"); number = 1; System.out.println("Trying a 1 digit integer in base 2"); result = rd.displayDigits2to9Base(number, 2); if(result.equals("1")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of 1"); number = 5; System.out.println("Trying a 1 digit integer in base 2"); result = rd.displayDigits2to9Base(number, 2); if(result.equals("1 0 1")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of 1 0 1"); number = 345; System.out.println("Trying a 3 digit integer in base 2"); result = rd.displayDigits2to9Base(number, 2); if(result.equals("1 0 1 0 1 1 0 0 1")) System.out.println(" Passed test"); else System.out.println("*** Failed test: returned " + result + " is not expected value of 1 0 1 0 1 1 0 0 1"); System.out.println(); System.out.println(); } }