// Test program for ourToUpper in Example 8.9

#include <iostream>
#include <cctype>

using namespace std;

const char YES = 'y';
const char NO  = 'n';

int main()
{
   
   char ourToUpper(char);  // prototypes 
   char getCharNewline();	 
   char getAnswer();
  
   char inChar;	                // input character to encode
   char answer; 		// answer to continue?

   cout << "This program prints the uppercase equivalent of a lowercase character."
        << endl;
   do
   {
	cout << "Enter a character: ";
	inChar = getCharNewline();

        cout << "The uppercase equivalent is " 
             << ourToUpper(inChar) << "." << endl;
	answer = getAnswer();
   }
   while (answer == YES);

   return 0;
}


//
// Function to read and return a character and to move the
// input buffer pointer past the newline character
// Pre: none
// Post: An input character was returned and the buffer flushed.
//

char getCharNewline()
{
   char inChar;

   cin.get(inChar);
   if (inChar != '\n') 
	cin.ignore(256, '\n');

   return inChar;
}


//
// Function to ask if user wishes to continue and to return
// the user's response after flushing the input buffer
// Pre: none
// Post: A y or an n was returned and the buffer flushed.
//

char getAnswer()
{
   char answer; 	// answer for wanting another code

   do
   {
	cout << endl << "Do you want to find another ASCII code? (y/n) ";
	answer = getCharNewline();
        answer = tolower(answer);
   }
   while ( !(answer == YES || answer == NO) );

   return answer;
}

//
// Example 8.9. Function to return uppercase equivalent of 
// lowercase letter ch. If ch is not a lowercase letter, 
// return ch.
// Pre:  ch is a character.
// Post: The uppercase equivalent of ch was returned.
//	 If ch was not a lowercase letter, ch was returned.

//
char ourToUpper(char ch) 
{

   char c;

   if ((ch < 'a') || (ch > 'z'))
	c = ch; 
   else 
	c = char(ch - 'a' + 'A');

   return c; 
}