Character Data type

• A character is a letter, digit or symbol.
• Actually it is anything listed on the ASCII character chart.
• The type is char
• To declare a variable of type char : char identifier;
• A literal of type char is enclosed in ', (single quotes or apostrophes).

• char aLetter;
  
  aLetter = 'x';
  
       

• There are some library functions to change the case of chars
  • char toupper(char) will convert a character to upper case if possible.
  • char tolower(char) will convert a character to lower case if possible.
  • You need to add #include <ctype.h>
• Output of characters: nothing special.
• Input of characters.
  • The standard input stream is cin
  • >> is the stream extraction operator.
  • cin >> theLetter; will read the next character typed on the keyboard and store it in theLetter.
• Design and implement a program which will read in three initials and print all permutations of those letter, in both upper and lower case.
  • Step 1, what do we want to do?

  • Input DaB  -> let's turn all the letters into upper case.
          DAB
    
          Permutations   abc acb
                         bac bca
    		     cab cba
    
         Output:
             DAB  DBA  ABD  ADB  BAD  BDA
    	  

  • Step 2, Algorithm

    Prompt the user for the first letter
    Read in the first letter
    Convert the first letter to upper case.
    
    Prompt the user for the second letter
    Read in the second letter
    Convert the second letter to upper case.
    
    Prompt the user for the third letter
    Read in the third letter
    Convert the third letter to upper case.
    
    Print abc, acb, bac, bca, cab, cba
    	  

  • Step 3, test the algorithm

    What if the user types in a non-letter (digit, symbol, ...) -> Just use it.
    	  

  • Step 4, implement the code.