// This program demonstrates several new concepts, including:
//   - String methods (charAt, length, etc.)
//   - fencepost loops
//   - String cumulative "sum"
import java.util.*;

public class LoopPractice {
   public static void main(String[] args) {
      System.out.println(doubleLetters("abcde"));
      System.out.println(doubleLetters("Mississippi"));
      System.out.println(doubleLetters("abracadabra"));
      System.out.println();
      
      spellOut("hello");
      spellOut("CSE142");
      spellOut("Happy Birthday");
      System.out.println();
      
      spellOutAlt("hello");
      spellOutAlt("CSE142");
      spellOutAlt("Happy Birthday");
      System.out.println();
   }
   
   // Returns a new String with each character from the given String
   //   doubled.
   // e.g. hello -> hheelllloo
   // Note that this is a form of a cumulative sum using Strings!
   //
   // String word - the String whose letters should be doubled
   public static String doubleLetters(String word) {
      String result = "";
      for (int i = 0; i < word.length(); i++) {
         // String letter = word.substring(i, i + 1);
         char letter = word.charAt(i);
         result = result + letter + letter;
      }
      return result;
   }   
   
   // Prints out the the characters in the given String separated
   //  by dashes.
   // e.g. hello -> h-e-l-l-o
   //
   // String word - the String to print
   public static void spellOut(String word) {
      System.out.print(word.charAt(0));
      for (int i = 1; i < word.length(); i++) {
         System.out.print("-" + word.charAt(i));
      }
      System.out.println();
   }
   
   // Alternate version of spellOut that removes the last instance
   //   of the fencepost instead of the first.
   //
   // String word - the String to print
   public static void spellOutAlt(String word) {
      for (int i = 0; i < word.length() - 1; i++) {
         System.out.print(word.charAt(i) + "-");
      }
      System.out.println(word.charAt(word.length() - 1));
   }
}