import java.util.Scanner; /** * This program implements two buggy methods that process strings. * * @author Jim Skrentny, copyright 2009-2011, all rights reserved */ public class StringBugs{ /** * Main program to test methods. * * @bugs none. */ public static void main(String[] args) { Scanner stdin = new Scanner(System.in); System.out.println("Enter a String: "); String str = stdin.next(); System.out.println("Enter a char: "); char ch = stdin.next().charAt(0); System.out.println("Character " + ch + " occurs " + countOccurrences(str, ch) + " times in string \"" + str + "\"."); System.out.println("\n\nEnter another String: "); str = stdin.next(); System.out.println("The reverse of string \"" + str + "\" is " + reverseString(str)); } /** * Counts the number of occurrences of char ch in String str. * * @param s - String to search for ch * @param c - char whose occurrence should be counted * @return int - the number of occurrences * * @bugs There are TWO minor errors. Can you find and fix them? */ public static int countOccurrences(String s, char c) { int count = 1; if (s != null) { for (int i = 1; i < s.length(); i++) { if (s.charAt(i) == c) { count++; } } } return count; } /** * Reverses the String. * * @param s - String to reverse * @return String - the reversed String * * @bugs There are TWO minor errors. Can you find and fix them? */ public static String reverseString(String s) { //toCharArray converts string s to an array of characters char[] swap = s.toCharArray(); //bugs are in the for loop for (int i = 1; i <= swap.length; i++) { char cTmp = swap[i]; swap[i] = swap[swap.length-i]; swap[swap.length-i] = cTmp; } //converts the swap array of characters back to a String return new String(swap); } }
