Objectives Chapter 12 Enumerated Structure and Union Types

Objectives Chapter 12 Enumerated, Structure, and Union Types ❏ To introduce the structure, union, and enumerated types ❏ To use the type definition statement in programs ❏ To use enumerated types, including anonymous types. ❏ To create and use structures in programs ❏ To be able to use unions in programs ❏ To understand the software engineering concept of coupling and to be able to evaluate coupling between functions. Computer Science: A Structured Programming Approach Using C 1

FIGURE 12 -1 Derived Types Computer Science: A Structured Programming Approach Using C 2

12 -1 The Type Definition (typedef) Before discussing the derived types, let’s discuss a C declaration that applies to all of them—the type definition. A type definition, typedef, gives a name to a data type by creating a new type that can then be used anywhere a type is permitted. Computer Science: A Structured Programming Approach Using C 3

FIGURE 12 -2 Type-definition Format Computer Science: A Structured Programming Approach Using C 4

12 -2 Enumerated Types The enumerated type is a user-defined type based on the standard integer type. In an enumerated type, each integer value is given an identifier called an enumeration constant. Topics discussed in this section: Declaring an Enumerated Type Operations on Enumerated Types Enumeration Type Conversion Initializing Enumerated Constants Anonymous Enumeration: Constants Input/Output Operations Computer Science: A Structured Programming Approach Using C 5

PROGRAM 12 -1 Print Cable TV Stations Computer Science: A Structured Programming Approach Using C 6

PROGRAM 12 -1 Print Cable TV Stations Computer Science: A Structured Programming Approach Using C 7

Note Don’t be confused about strings and enumerated types. “cnn” is a string made of three characters; cnn, as defined in the previous code example, is an enumerated type (identifier) which has the integer value 51. Computer Science: A Structured Programming Approach Using C 8

12 -3 Structure A structure is a collection of related elements, possibly of different types, having a single name. Topics discussed in this section: Structure Type Declaration Initialization Accessing Structures Operations on Structures Complex Structures and Functions Computer Science: A Structured Programming Approach Using C 9

FIGURE 12 -3 Structure Examples Computer Science: A Structured Programming Approach Using C 10

Note Elements in a structure can be of the same or different types. However, all elements in the structure should be logically related. Computer Science: A Structured Programming Approach Using C 11

FIGURE 12 -4 Tagged Structure Format Computer Science: A Structured Programming Approach Using C 12

FIGURE 12 -5 Structure Declaration with typedef Computer Science: A Structured Programming Approach Using C 13

FIGURE 12 -6 Structure Declaration Format and Example Computer Science: A Structured Programming Approach Using C 14

FIGURE 12 -7 Initializing Structures Computer Science: A Structured Programming Approach Using C 15

FIGURE 12 -8 Structure Direct Selection Operator Computer Science: A Structured Programming Approach Using C 16

PROGRAM 12 -2 Multiply Fractions Computer Science: A Structured Programming Approach Using C 17

PROGRAM 12 -2 Multiply Fractions Computer Science: A Structured Programming Approach Using C 18

FIGURE 12 -9 Copying a Structure Computer Science: A Structured Programming Approach Using C 19

FIGURE 12 -10 Pointers to Structures Computer Science: A Structured Programming Approach Using C 20

Note (*pointer. Name). field. Name Computer Science: A Structured Programming Approach Using C « pointer. Name->field. Name. 21

FIGURE 12 -11 Interpretation of Invalid Pointer Use Computer Science: A Structured Programming Approach Using C 22

FIGURE 12 -12 Indirect Selection Operator Computer Science: A Structured Programming Approach Using C 23

PROGRAM 12 -3 Clock Simulation with Pointers Computer Science: A Structured Programming Approach Using C 24

PROGRAM 12 -3 Clock Simulation with Pointers Computer Science: A Structured Programming Approach Using C 25

PROGRAM 12 -3 Clock Simulation with Pointers Computer Science: A Structured Programming Approach Using C 26

PROGRAM 12 -3 Clock Simulation with Pointers Computer Science: A Structured Programming Approach Using C 27

FIGURE 12 -13 Nested Structure Computer Science: A Structured Programming Approach Using C 28

FIGURE 12 -14 Arrays in Structures Computer Science: A Structured Programming Approach Using C 29

FIGURE 12 -15 Pointers in Structures Computer Science: A Structured Programming Approach Using C 30

FIGURE 12 -16 Array of Structures Computer Science: A Structured Programming Approach Using C 31

PROGRAM 12 -4 Sort Array of Student Structures Computer Science: A Structured Programming Approach Using C 32

PROGRAM 12 -4 Sort Array of Student Structures Computer Science: A Structured Programming Approach Using C 33

PROGRAM 12 -4 Sort Array of Student Structures Computer Science: A Structured Programming Approach Using C 34

PROGRAM 12 -4 Sort Array of Student Structures Computer Science: A Structured Programming Approach Using C 35

PROGRAM 12 -4 Sort Array of Student Structures Computer Science: A Structured Programming Approach Using C 36

PROGRAM 12 -4 Sort Array of Student Structures Computer Science: A Structured Programming Approach Using C 37

FIGURE 12 -17 Passing Structure Members to Functions Computer Science: A Structured Programming Approach Using C 38

FIGURE 12 -18 Passing and returning structures Computer Science: A Structured Programming Approach Using C 39

PROGRAM 12 -5 Passing and Returning Structures Computer Science: A Structured Programming Approach Using C 40

PROGRAM 12 -5 Passing and Returning Structures Computer Science: A Structured Programming Approach Using C 41

PROGRAM 12 -5 Passing and Returning Structures Computer Science: A Structured Programming Approach Using C 42

PROGRAM 12 -5 Passing and Returning Structures Computer Science: A Structured Programming Approach Using C 43

PROGRAM 12 -5 Passing and Returning Structures Computer Science: A Structured Programming Approach Using C 44

FIGURE 12 -19 Passing Structures Through Pointers Computer Science: A Structured Programming Approach Using C 45

PROGRAM 12 -6 Passing Structures through Pointers Computer Science: A Structured Programming Approach Using C 46

PROGRAM 12 -6 Passing Structures through Pointers Computer Science: A Structured Programming Approach Using C 47

PROGRAM 12 -6 Passing Structures through Pointers Computer Science: A Structured Programming Approach Using C 48

PROGRAM 12 -6 Passing Structures through Pointers Computer Science: A Structured Programming Approach Using C 49