/* T01n12.java -- Given a message typed by the user, find all periods and
 * replace them with exclamation points, and find all exclamation points
 * and add another exclamation point after each one.  For example:
 *   Hey! Slow down.  --->  Hey!! Slow down! 
 *
 * This is the first of three examples that do this same task, but in 
 * different ways:
 *
 *    T01n12.java -- Using Strings, build the new string a character at a time
 *    T01n13.java -- Still using only Strings, use substring() to build the
 *                   new string in chunks (uses fewer concatenations).
 *    T01n14.java -- Convert the input into a StringBuilder object and
 *                   manipulate it directly.
 *
 * And, yes, I'm jumping the gun a bit by introducing a user-defined method
 * to these examples.  We'll be covering those soon, and I think you'll
 * be able to make sense out of this now, given your backgrounds in other
 * programming languages.
 */

import java.util.*;

public class T01n12
{
    public static void main (String [] args)
    {
        String message;                     // User's boring/exciting message
        Scanner keyboard = new Scanner (System.in);  // Input is from keyboard

        System.out.print("Please type in a message : "); 
        message = keyboard.nextLine();

        message = addExcitement(message);  // What do you think of this line?

        System.out.println("\nThank you.  If you had been more excited, "
                         + "you'd have typed your message\nlike this:\n\t"
                         + message);
    }

            /* This version of addExcitement scans the message character by
             * character, and builds up the new string almost character by
             * character.  Note that no StringBuilder objects are used
             * (or harmed) in the execution of this program.
             *
             * For fun, try initializing excited to null instead of to the
             * empty string, and run the program.
             */

    private static String addExcitement (String original)
    {
        String excited = "";   // Reference to built-up resulting message
        char currentChar;      // Holds each char of orig. message in turn

        for (int i=0; i < original.length(); i++) {

            currentChar = original.charAt(i);

            if (currentChar == '.') {
                excited = excited + '!';
            } else if (currentChar == '!') {
                excited = excited + "!!";
            } else {
                excited = excited + currentChar;
            }

        }

        return excited;
    }

}