public class ReverseString { public static void main(String[] args) { String s1 = "neelendra"; for(int i=s1.length()-1;i>=0;i--) { System.out.print(s1.charAt(i)); } }
}

// Iterative java program to reverse an
// array
public class GFG {
     
   /* Function to reverse arr[] from
    start to end*/
    static void rvereseArray(int arr[],
                    int start, int end)
    {
        int temp;
          
        while (start < end)
        {
            temp = arr[start];
            arr[start] = arr[end];
            arr[end] = temp;
            start++;
            end--;
        }
    }    
      
    /* Utility that prints out an
    array on a line */
    static void printArray(int arr[],
                            int size)
    {
        for (int i = 0; i < size; i++)
             System.out.print(arr[i] + " ");
          
         System.out.println();
    }
 
    // Driver code
    public static void main(String args[]) {
         
        int arr[] = {1, 2, 3, 4, 5, 6};
        printArray(arr, 6);
        rvereseArray(arr, 0, 5);
        System.out.print("Reversed array is \n");
        printArray(arr, 6);
        
    }
}
 

package com.javaguides.strings.examples;
/** * 5 ways to reverse a String in Java * @author javaguides.net * */
public class ReverseString5Ways { public static void main(String[] args) { reverseWithStringConcat("javaguides"); reverseWithStringBuilder("javaguides"); reverseWithStringBuilderBuiltinMethod("javaguides"); reverseWithSwaps("javaguides"); reverseWithXOR("javaguides"); } public static final String reverseWithStringConcat(String string) { String output = new String(); for (int i = (string.length() - 1); i >= 0; i--) { output += (string.charAt(i)); } display(string, output); return output; } public static final String reverseWithStringBuilder(String string) { final StringBuilder builder = new StringBuilder(); for (int i = (string.length() - 1); i >= 0; i--) { builder.append(string.charAt(i)); } display(string, builder.toString()); return builder.toString(); } public static final String reverseWithStringBuilderBuiltinMethod(String string) { final StringBuilder builder = new StringBuilder(string); display(string, builder.reverse().toString()); return builder.reverse().toString(); } public static final String reverseWithSwaps(String string) { final char[] array = string.toCharArray(); final int length = array.length - 1; final int half = (int) Math.floor(array.length / 2); char c; for (int i = length; i >= half; i--) { c = array[length - i]; array[length - i] = array[i]; array[i] = c; } display(string, String.valueOf(array)); return String.valueOf(array); } public static final String reverseWithXOR(String string) { final char[] array = string.toCharArray(); final int length = array.length; final int half = (int) Math.floor(array.length / 2); for (int i = 0; i < half; i++) { array[i] ^= array[length - i - 1]; array[length - i - 1] ^= array[i]; array[i] ^= array[length - i - 1]; } display(string, String.valueOf(array)); return String.valueOf(array); } private static final void display(String original, String reverse) { System.out.println(original); System.out.println(reverse); System.out.println("----------------------------"); }
}