Sections 0101, 0102, 0103 and Honors, Fall 1995

Tuesday October 31, 1995

Assigned Reading: 9.2 - 9.3

Handouts (available on-line): none

Topics Covered:

• A quick look at enumeration types.
  • We can use enumerations to represent colors of the rainbow. Program and sample run.
  • Enumerations do not have to begin at 0. We can use red to represent 1 instead of 0, as shown in this program and sample run.
  • We can use the typedef facility to make an new type called rainbow. In this program, variables are declared with type rainbow. Note that just like the more familiar type int, rainbow can be the type of return values and parameters too. Sample run.

• Characters are similar to enumeration types because their internal representation is an integer. However, we would like to think of characters as letters, digits, punctuation marks, etc, and not as a number. Nevertheless, it is sometimes useful to use the fact that the letter A is followed by the letter B, etc. Here's a program that uses for loops to step through the letters of the alphabet.

• We can list the entire ASCII character set using the following program. Note that in the output, not all characters are printable. Special characters are denoted using the backslash symbol as done in the following program and Sample run.

• The standard functions that work with characters are in the ctype.h interface. The following UNIX manual pages for ctype.h describe the purpose of the functions.

• Strings are sequences of characters. We will be using the strlib.h interface from the course library. Here's a program that prints out the user's input in upper case. A modified version of the program stores the upper case version of the user's input in a new string. The sample run shows that the original string and the new string can be printed out.