package algorithm; public class ReverseString { public static void main(String args[]) { //original string String str = "Sony is going to introduce Internet TV soon"; System.out.println("Original String: " + str); //reversed string using Stringbuffer String reverseStr = new StringBuffer(str).reverse().toString(); System.out.println("Reverse String in Java using StringBuffer: " + reverseStr); //iterative method to reverse String in Java reverseStr = reverse(str); System.out.println("Reverse String in Java using Iteration: " + reverseStr); //recursive method to reverse String in Java reverseStr = reverseRecursively(str); System.out.println("Reverse String in Java using Recursion: " + reverseStr); str = "abc"; System.out.println("str.length()" + str.length()); System.out.println("str.substring(0)" + str.substring(0)); System.out.println("str.substring(1)" + str.substring(1)); System.out.println("str.substring(0,str.length())" + str.substring(0,str.length())); System.out.println("str.substring(0,str.length()-1)" + str.substring(0,str.length() -1)); System.out.println("str.substring(1,3)" + str.substring(1,3)); } public static String reverse(String str) { StringBuilder strBuilder = new StringBuilder(); char[] strChars = str.toCharArray(); for (int i = strChars.length - 1; i >= 0; i--) { strBuilder.append(strChars[i]); } return strBuilder.toString(); } public static String reverseRecursively(String str) { // System.out.println(" reverseRecursively Calling str: "+ str); //base case to handle one char string and empty string if (str.length() < 2) { // System.out.println(" reverseRecursively returing str: "+ str); return str; } // System.out.println(" reverseRecursively befor returing str.substring(1): "+ str.substring(1) + ", str.charAt(0):"+ str.charAt(0)); return reverseRecursively(str.substring(1)) + str.charAt(0); } }