//********************************************************************
//
// Telephone.java
// Program title: This is the title 
//
//********************************************************************
//
// Program Description and Design Overview:
//      Prompt user to enter a single letter from A through Z (upper case only) 
//	Input a single letter (type char) 
//	Print out the corresponding digit (an int) of the buttons on a phone pad with the message: 
//	"The digit N corresponds to the letter L on the telephone" 
//	(where L is the letter typed by the program user and N is the corresponding digit computed by the program) 
//	The digit-letter correspondence rules are: 
//	2 = ABC,  3 = DEF,  4 = GHI,  5 = JKL,  6 = MNO, 7 = PRS, 8 = TUV, 9 = WXY 
//	Use a multi-way if -else statement for this solution. Do not use a switch statement. 
//	Hint: You will need to use the logical OR operator (see page 123, 124 of your textbook) 
//	Since only certain upper case letters correspond to a phone pad digit, any other letter or character will not have a corresponding digit. Thus, if any other character is entered, the program should print, 
//
//	"There is no digit on the telephone that corresponds to L" 
//	(where L is the letter entered)

// Input Requirements:  char letter- the capitalized letter
//      				answer- answer to question "Do you want to enter another character?"
//
// Output Requirements: 
//		Prompts for the conditions under which the user must follow in order to input the letter.
//      The number corresponding to the letter typed in.
//
// Program Preconditions:The user must input capitalized letters to get the 
// 				result they are looking for.
//      
//
//********************************************************************

import cs1.Keyboard;

public class Telephone
{
   char letter; //the capitalized letter to be changed into a number
   

   //-----------------------------------------------------------------
   // Prints the number corresponding to the "capital" letters on a telephone pad.
   //-----------------------------------------------------------------
   public static void main (String[] args)
   {
   	String answer = "yes"; //initialized condition to start the program
   	
   	while (answer.equals("yes"))
	{
	System.out.print ("Please type a letter A through P or R through Y: ");
	char letter = Keyboard.readChar(); //inputs user response to variable letter

	// inner loop of the nested loop
	while (letter != 'A' && letter != 'B' && letter != 'C' && letter != 'D' && letter != 'E' 
			&& letter != 'F' && letter != 'G' && letter != 'H' && letter != 'I' && letter 
			!= 'J' && letter != 'K' && letter != 'L' && letter != 'M' && letter != 'N' && 
			letter != 'O' && letter != 'P' && letter != 'R' && letter != 'S' && letter != 'T' 
			&& letter != 'U' && letter != 'V' && letter != 'W' && letter != 'X' && 
			letter != 'Y')// executes loop if the letter is invalid
	{
		System.out.println ("Sorry, " + letter + " is not valid.");
		System.out.print ("Please type a letter A through P or R through Y: ");
		letter = Keyboard.readChar(); //inputs user response into variable letter
	}

	if ( letter == 'A' || letter == 'B' || letter == 'C' )
		{System.out.println ("The digit 2 corresponds to the letter " + 							letter + " on the telephone pad");}

	else if ( letter == 'D' || letter == 'E' || letter == 'F' )
		{System.out.println ("The digit 3 corresponds to the letter " + 									letter + " on the telephone pad");}
		
	else if ( letter == 'G' || letter == 'H' || letter == 'I' )
		{System.out.println ("The digit 4 corresponds to the letter " + 														letter + " on the telephone pad");}
		
	else if ( letter == 'J' || letter == 'K' || letter == 'L' )
		{System.out.println ("The digit 5 corresponds to the letter " + 					letter + " on the telephone pad");}
		                                                                                          
	else if ( letter == 'M' || letter == 'N' || letter == 'O' )
		{System.out.println ("The digit 6 corresponds to the letter " + 					letter + " on the telephone pad");}
		
	else if ( letter == 'P' || letter == 'R' || letter == 'S' )
		{System.out.println ("The digit 7 corresponds to the letter " + 					letter + " on the telephone pad");}
		
	else if ( letter == 'T' || letter == 'U' || letter == 'V' )
		{System.out.println ("The digit 8 corresponds to the letter " + 					letter + " on the telephone pad");}
		
	else if ( letter == 'W' || letter == 'X' || letter == 'Y' )
		{System.out.println ("The digit 9 corresponds to the letter " + 					letter + " on the telephone pad");}
		
	else System.out.println ("Sorry, " + letter + " is not valid.");
	
	System.out.println ("Do you want to enter another character? "); //prompts user if they want to enter another character
	answer = Keyboard.readString();//inputs user response to string variable answer

}
   } //end main

} // end class Telephone