How to print a through z using a recursive method

Question

Hi new to java here and I need to print the alphabet from a to z and in reverse from z to a. I need to do this using a recursive method.

class Alphabets{


public static void main(String args[]){
  char ch;
  for( ch = 'a' ; ch <= 'z' ; ch++ )
    System.out.print(ch);
  System.out.println();
  for( ch = 'z' ; ch >= 'a' ; ch--)
     System.out.print(ch);

  if (ch <= 'a') ch = ch--;
    else if(ch >='a') ch = ch++;
    System.out.print(ch);

 }
}

My output for the two for loops seems to work just fine but I am completely lost on the recursive method.

In your code dnt see any recursion being used? What have you tried? — Narendra Pathai, Oct 24 '13 at 06:45

score 1 · Answer 1 · answered Oct 24 '13 at 06:49

This is how to do it :

public static void main(String[] args) {
    recursiveAlphabet('a');
    recursiveAlphabetReverse('z');
}

public static void recursiveAlphabet(char current) {
    System.out.println(current);
    if (current != 'z') {
        recursiveAlphabet((char) (current + 1));
    }
}

public static void recursiveAlphabetReverse(char current) {
    System.out.println(current);
    if (current != 'a') {
        recursiveAlphabetReverse((char) (current - 1));
    }
}

If you need, you can have both in one method, which looks like this :

public static void main(String[] args) {
    resursiveBothSide('a', true);
}

public static void resursiveBothSide(char current, boolean forward) {
    System.out.println(current);
    if ((current == 'z') && (forward)) {
        forward = false;
    }
    if (forward) {
        resursiveBothSide((char) (current + 1), forward);
    } else {
        if (current != 'a') {
            resursiveBothSide((char) (current - 1), forward);
        }
    }
}

Osiris · Accepted Answer · 2013-10-24T06:53:39.810

0

public static void printCharRecur(char ch) {
 if(ch=='z') System.out.print("z z");
 else {
  System.out.print(ch);
  printCharRecur((char) (ch+1));
  System.out.print(ch);
 }
}

Call printCharRecur('a') from main

edited Oct 24 '13 at 06:53

answered Oct 24 '13 at 06:45

Osiris

4,195
2
22
52

score 0 · Answer 3 · answered Oct 24 '13 at 06:47

To print an alphabet in forward direction: print the first character of the alphabet, then print an alphabet without the first character.

To print it in reverse, just reverse the order of those two: print an alphabet without the first character, then print the first character.

score 0 · Answer 4 · answered Oct 24 '13 at 06:52

0

Do below as simple just remove your if condition:-

char ch;
          for( ch = 'a' ; ch <= 'z' ; ch++ )
            System.out.print(ch);
          System.out.println();
          for( ch = 'z' ; ch >= 'a' ; ch--)
             System.out.print(ch);

answered Oct 24 '13 at 06:52

Hussain Shabbir

14,801
5
40
56

_"My output for the two for loops seems to work just fine but I am completely lost on the **recursive method**"_ – Alexis C. Oct 24 '13 at 06:53
I mean that the OP wants to know how to do that recursively. – Alexis C. Oct 24 '13 at 06:57
But where is the recursive method?? – Hussain Shabbir Oct 24 '13 at 06:58
Actually this is the question he asked (_"I am completely lost on the recursive method"_). – Alexis C. Oct 24 '13 at 07:05

score 0 · Answer 5 · answered Oct 24 '13 at 07:07

0

Here with simple, single method and without - :

void printrec(char c) {
    if (c > 'z') return;
    System.out.print(c);
    printrec((char) (c+1));
    System.out.print(c);
}

answered Oct 24 '13 at 07:07

Ingo

36,037
5
53
100

Deepak Gauttam · Answer 6 · 2022-09-22T19:51:30.313

0

    import java.util.*;
    import java.io.*;
    
    public class Main
    {
        static void print(char n){
            if(n=='z'){
               System.out.print(n);
                return;
            }
        
            System.out.print(n+" ");
            print((char)(n+1)) ;
        }
        public static void main(String [] arg){
            print('a');
        }
    }

/*
Output:  a b c d e f g h i j k l m n o p q r s t u v w x y z
*/

edited Sep 22 '22 at 19:51

answered Sep 22 '22 at 19:45

Deepak Gauttam

23
4

As it’s currently written, your answer is unclear. Please [edit] to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – abdo Salm Sep 27 '22 at 02:02

How to print a through z using a recursive method

6 Answers6