Chapter 13 Introduction to C Language

1
Chapter 13 Introduction to C Language

• By C. Shing
• ITEC Dept
• Radford University

2
Objectives

• Understand C features
• Understand Program Structure in C

3
C Features

• Type language (stronger type than C)
• Variable must be declared a type
• (declaration mixed with statements)
• has boolean data type bool (false, true)
• Class hide member data (only member function can
  access them),
• provide public interface by member function
• Overloading (operator and function)
• same function/operator name with different
• argument list
• Inheritance and Polymorphism virtual function
• Template
• Same function task for different data types

4
Running C Program

• C source program -gt C Compiler
• -gt Object program -gt Link
• -gt(feed data) Excution

5
Program Structures

• File Extension
• .cc (or .cpp)
• Compile link (Solaris) , then execute
• g mainfile.cc sub1filename.cc
  sub2filename.cc
• then
• a.out
• or
• g -o executable mainfile.cc
• sub1filename.cc sub2filename.cc
• then
• executable

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Program Structures (Cont.)

• Compile only (Solaris)
• g c filename.cc

7
Program Structures (Cont.)

• mainfile.cc
• /
• This is a comment
• Block
• /
• // Comment line
• // Declaration for standard library
• // The following line is required
• include ltiostreamgt

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Program Structures (Cont.)

• // all C library declaration starts with c
• include ltcmathgt //if math library is used
• // The following file yourdeclaration.h
• // is in your current directory
• //include yourdeclaration.h
• using namespace std // for cin and cout
• // declare named global constants
• const int number 4
• const double PI 3.14159
• const char MY_MESSAGE Good Morning!

9
Program Structures (Cont.)

• // declare types
• typedef char myCharacter
• // declare global variables
• int a
• char ba, c\n
• myCharacter e
• long d 14000L // this means long int (default
  int)
• float x-2.5F
• double y2.5

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Program Structures (Cont.)

• // declare function prototype
• int sub1(int)
• // define main function
• int main ()
• int lc 2
• // call function
• int lb sub1(lc)
• cout ltlt lb ltltendl
• return 0 // no error exit

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Program Structures (Cont.)

• // define function
• int sub1 (int l)
• // call function
• int la 5l
• return la

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Variable

• Variable declaration
• Form type variable initial value
• e.g. int number
• Pointer variable declaration
• Form type variable initial value
• e.g. int numberptr0
• // numberptr is initialized to null pointer

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Constant Variable

• Constant variable declaration
• Form const type variable
• e.g. const double PI 3.14159
• Constant address (or pointer variable)
• declaration
• Form pointer type const variable
• e.g. double const PIptr

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Variable (Cont.)

• Constant address points to constant variable
• declaration
• Form const pointer type const variable
• e.g. const double const PIptr
• Alias or reference variable
• (must initialize when declare it)
• Form type aliasvariable
• e.g. int number10
• int numberaliasnumber

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Difference Between Alias and Pointer

• Alias must have variable value (not null).
• Pointer can be null.
• Alias will not be reassigned once declared,
• only the value will be changed
• Alias can access the variable directly,
• pointer accesses the variable indirectly

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Difference Between Alias and Pointer (Cont.)

• Example
• ref.cc

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Assignment Statement

• Casting
• Identifier static_castltleft hand side typegt
  (expression)
• Example int number static_castltintgt(3.1416)
• Then number contains 3

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Loop Statement for (Cont.)

• Example
• // loop index can be defined inside for loop
  
• // and only meaningful within the loop
• for (int i0ilt5i)
• cout ltlt TRUE is printed!\n // print 5
  times

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Format Data Stream

• Need include ltiomanipgt
• setw() set total of spaces to print
• if not enough, give exact of spaces needed
• setiosflags(iosfixediosshowpoint)
• print decimal point
• setprecision()
• set total of spaces after decimal point
• format.cc

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Example without Using Class

• Example 1
• hello.cc
• hello1.cc
• hello2.cc

21
Program Structures (Using Class)

• Problem Write a class Dice to simulate
• flipping two dices.
• Example 2

22
Program Structures (Using Class)- Cont.

• Problem Write a class Dice to simulate
• flipping two dices. (Cont.)
• Use Modules
• driver
• class implementation
• class specification
• header file

23
Compare C to Java Program

• Problem Write a class Dice to simulate
• flipping two dices.
• Example 3
• dice.java

24
Reference

• Deitel Deitel C How to Program, 4th ed.,
• Chapter 15, Prentice Hall