CONTROL STRUCTURES II: REPETITION - Java Programming: From Problem Analysis to Program Design - page 260

inputMessage = "Program to convert uppercase "
+ "letters to their corresponding "
+ "telephone digits.\n"
+ "To stop the program enter #.\n"
+ "Enter a letter:"; //Line 5

inputString =
JOptionPane.showInputDialog(inputMessage); //Line 6

letter = inputString.charAt(0); //Line 7

while (letter != '#' ) //Line 8

{

outputMessage = "The letter you entered is: "
+ letter + "\n"
+ "The corresponding telephone "
+ "digit is: "; //Line 9

if (letter >= 'A' && letter <= 'Z') //Line 10

{

switch (letter) //Line 11

{
case 'A':
case 'B':
case 'C':
outputMessage = outputMessage
+ "2"; //Line 12

break ; //Line 13

case 'D':
case 'E':
case 'F':
outputMessage = outputMessage
+ "3"; //Line 14

break ; //Line 15

case 'G':
case 'H':
case 'I':
outputMessage = outputMessage
+ "4"; //Line 16

break ; //Line 17

case 'J':
case 'K':
case 'L':
outputMessage = outputMessage
+ "5"; //Line 18

break ; //Line 19