Printing reverse of any String without using any predefined function?

Question

How to print the reverse of the String java is object orientated language without using any predefined function like reverse()?

Answer 1

This is the simplest solution:

System.out.print("egaugnal detatneiro tcejbo si avaj");

Answer 2

Here you go:

public static void main (String[] args) {
    System.out.println(reverserString("Akshay"));
}

private static String reverserString(String src) {
    char[] sArr = src.toCharArray();
    char[] dArr = new char[sArr.length];
    for(int i=sArr.length; i>0; i--) {
        dArr[sArr.length-i] = sArr[i-1];
    }

    return new String(dArr);
}

Answer 3

First of all: Why reinvent the wheel?

That being said: Loop from the length of the string to 0 and concatenate into another string.

Answer 4

public class MyStack {
   private int maxSize;
   private char[] stackArray;
   private int top;
   public MyStack(int s) {
      maxSize = s;
      stackArray = new char[maxSize];
      top = -1;
   }
   public void push(char j) {
      stackArray[++top] = j;
   }
   public char pop() {
      return stackArray[top--];
   }
   public char peek() {
      return stackArray[top];
   }
   public boolean isEmpty() {
      return (top == -1);
   }
   public boolean isFull() {
      return (top == maxSize - 1);
   }
   public static void main(String[] args) {
      MyStack theStack = new MyStack(10);
      String s="abcd";
      for(int i=0;i<s.length();i++)
      theStack.push(s.charAt(i));
      for(int i=0;i<s.length();i++)
      System.out.println(theStack.pop());

    }

Answer 5

What is suprising is that most of the answers are wrong! When Unicode is used. Seems like no one understands that java uses UTF-16 under the hood for Text encoding.

Here is my simple answer.

static String reverseMe(String s) {
   StringBuilder sb = new StringBuilder();

   int count = s.codePointCount(0,s.length());
   for(int i = count - 1; i >= 0; --i)
     sb.append(Character.toChars(s.codePointAt(i)));

   return sb.toString();
 }

Answer 6

How about a simple traverse from the end of the string to the beg:

void printRev(String str) {
 for(int i=str.length()-1;i>=0;i--)
  System.out.print(str.charAt(i));
}