Week 4 Objectives

KNOW:

• why it is useful to be able to organize functions into libraries
• which information should go into a header file, which information should go into an implementation file, and which information should go into an applications program
• That a string is a pointer to a null-terminated array of char
• The difference between declaring a string as a pointer to a char, and as an array of char
• The string manipulation functions of the string handling library
• The comparison functions of the string handling library
• The search functions of the string handling library
• that a struct can be used to group together variables of different types
• that the keyword typedef provides a mechanism for creating synonyms for previously defined types

BE ABLE TO:

• create a library of user-defined functions
• draw a dependency diagram for a program that spans multiple files
• create a makefile to manage a multi-file program
• Declare a string using a pointer to a char, or an array of char
• Use I/O statements scanf, fgets, printf, puts to input and output strings
• Write a function that uses array subscripts to process a string
• Write a function that uses pointers to process a string
• Choose and use the appropriate functions from the string handling library when working with strings
• define a struct
• access individual members of a struct
• pass a struct to a function, using either call-by-value or call-by-reference
• define and use an array of struct
• use typedef to define a struct type

Sample Quiz Questions:

1. Create a makefile for a program that has two header files (board.h and useful.h), and three source files (board.c, useful.c, and game.c). The source files contain these include directives:

   board.c:   #include "board.h"
              #include "useful.h"
   
   
   useful.c:  #include "useful.h"
   
   
   game.c:    #include "board.h"
              #include "useful.h"
   

   (Hint: draw a dependency diagram first)

2. Write a function that will capitalize all the vowels in a string. Here are the pre- and post-conditions for the function, and the function heading:

   PRE:  string1 is a string.  string2 points to an array with length >= strlen(string1)
   POST: string2 is a string identical to string1, except that all vowels
         in string1 have been converted to capital letters in string2
   
         void bigVowels (const char *string1, char *string2)
   

   Use pointers to solve this problem (don't use array subscripts). You may use the function toupper() (from ctype.h).

3. Assume that variable ptr is of type char *, and arrays s1[100] and s2[100] are of type char. Write a C statement that will assign ptr the location of the first occurrence of the string s2 in s1.

4. Using the struct book example from today's handout, define an array called library that can contain information for as many as 1000 books. Assume the array has been filled in with information. Write a statement that will determine the number of characters in the author's name for the book at location 5 in the array.