Programming with C

1
Programming with C
Jun Ni, Ph.D.M.E. Department of Computer
Science The University of Iowa Fall, 2002
2
Introduction
3
Introduction

• Introduction

4
Introduction

• Structural programming (SP) and object-oriented
  programming (OOP) language.
• Superset of C.
• One of most popular software development
  programming.
• ANSI/ISO standard.
• Standard library
• Scalable and potable.
• Distributed computing and grid computing

5
Introduction

• What you should prepare before learning C?
• Your commitment.
• Basic computer hardware knowledge (I/O devices,
  memory, ALU, CPU, secondary storage,
• Computer software knowledge (OS, languages,
  compiler and interpreter, )

6
Introduction

• History
• C was evolved by Denis Ritchie at Bell Lab in
  1972 when he developed UNIX. It becomes standard
  in 1990.
• C, an extension of C was developed by Bjarne
  Stoustrup in the early 1980s at Bell Lab. OOP was
  provided in, which is a revolution of computer
  programming.
• C has standard library.

7
Introduction

• The main pieces of learning C is
• to learn C language
• to learn how to use standard library (classes and
  functions), and special C library .
• The final goal is
• to apply these libraries to your own applications
• to develop your own library for your use or
  contribute own library to computer world

8
Introduction

• What else we should know or learn? JAVA!
• Java is another popular programming language
• Java is very portable
• Incorporates features of C/C and other OOP
• easy to apply to web applications through Java
  applets
• How about other popular languages?
• Fortran, COBOL, Pascal, ...

9
Introduction

• How to run C programs?
• Use any word processing tools to create a C
  code in terms of text file, or ASCII format.
• C files are ended with .cpp, .cxx, or .C
• Then compile and link C files
• Finally execute the executable file created
• If find bugs or errors, go back to the first step
  and correct them and try again.

10
Introduction

• How? How? How?
• On UNIX, use UNIX commands
• On PC, use Visual C (see handout)

CC myfirst.cpp a.out
or
CC -o myfirst myfirst.cpp myfirst
11
Introduction

• First C program

// Fig. 1.2 fig1_02.cpp // A first program in
C include ltiostream.hgt int main()
stdcout ltlt "Welcome to C!\n" // indicate
that program ended successfully return 0
comment
Preprocessor directive
function
body
12
Introduction

• result

Welcome to C!
13
Introduction

• Escape sequence characters

\n \t \r \a \\ \" \v \b \r \? \'
14
Introduction

• Revised First C program

// Fig. 1.4 fig1_4.cpp // Printing a line with
multiple statements include ltiostream.hgt int
main() stdcout ltlt "Welcome " stdcout
ltlt "to C!\n" // indicate that program ended
successfully return 0 Result
Welcome to C!
15
Introduction

• More new lines added in the first C program

// Fig. 1.5 fig1_05.cpp // Printing multiple
lines with a single statement include
ltiostream.hgt int main() stdcout ltlt
"Welcome\nto\n\nC!\n" // indicate that program
ended successfully return 0
16
Introduction

• Result

Welcome to C!
17
Introduction

• Adding two integers (input and output)

// Fig. 1.6 fig1_06.cpp // Addition
program include ltiostream.hgt int main()
int integer1, integer2, sum // declaration
std cout ltlt "Enter first integer\n" //
prompt std cin gtgt integer1 // read
an integer std cout ltlt "Enter second
integer\n" // prompt std cin gtgt integer2
// read an integer
18
Introduction

• Adding two integers
• Result

sum integer1 integer2 // assignment of
sum std cout ltlt "Sum is " ltlt sum ltlt endl //
print sum // indicate that program ended
successfully return 0
Enter first integer 45 Enter second
integer 72 Sum is 117
19
Introduction

• Arithmetic operators
• Examples

- /
f7 p-c bm x/y rs
20
Introduction

• Rules of arithmetic operator precedence

( ) inside to outside / left to
right - left to right
Example (34) 5 2 /(32-1) 83
21
Introduction

• Assignment operator (right to left)
• example a 32 a a-2
• Additional assignment operators
• - /

a2
aa2
a-2
aa-2
cc2
c2
cc/2
c/2
cc2
c2
22
Introduction

• Increment/decrement operators --
• count i
• j-- --k
• (pre-increment/decrement)
• (post-increment/decrement)

23
Introduction

• Example

// Preincrementing and postincrementing include
ltiostream.hgt int main() int c c 5
std cout ltlt c ltlt endl // print 5
std cout ltlt c ltlt endl // print 5 then
postincrement std cout ltlt c ltlt endl ltlt endl
// print 6
24
Introduction

• Example

c 5 cout ltlt c ltlt endl // print
5 cout ltlt c ltlt endl // preincrement
then print 6 cout ltlt c ltlt endl //
print 6 return 0 //
successful termination
25
Introduction

• Equality operator
• Example a2 j(i-k)
• relational operators gt gt lt lt
• Example agtb hgt12 clta jltk-1
• logical operators !
• Example a!10 alt2 agt10 bgt4 agt3
• ! (agt3)

26
Introduction
( relational test 1) ( relational test2)
relational test 1 relational rest 2
(false) (true)
false
relational test 1 (false) relational test 2
(true)
false
false
true
27
Introduction
( relational test 1) ( relational rest2)
relational test 1 relational rest 2
(false) (true)
true
relational test 1 (false) relational test 2
(true)
false
true
true
28
Introduction
! ( relational test )
relational test (false) relational test (true)
true
false
29
Introduction

• Relational operator example

// Fig. 1.14 fig01_14.cpp // Using if
statements, relational // operators, and equality
operators include ltiostreamgt using stdcout
// program uses cout using stdcin // program
uses cin using stdendl // program uses endl
30
int main() int num1, num2 cout ltlt
"Enter two integers, and I will tell you\n"
ltlt "the relationships they satisfy " cin
gtgt num1 gtgt num2 // read two integers if (
num1 num2 ) cout ltlt num1 ltlt " is equal
to " ltlt num2 ltlt endl if ( num1 ! num2 )
cout ltlt num1 ltlt " is not equal to " ltlt num2 ltlt
endl
31
if ( num1 lt num2 ) cout ltlt num1 ltlt " is
less than " ltlt num2 ltlt endl if ( num1 gt num2
) cout ltlt num1 ltlt " is greater than " ltlt
num2 ltlt endl if ( num1 lt num2 ) cout
ltlt num1 ltlt " is less than or equal to "
ltlt num2 ltlt endl if ( num1 gt num2 ) cout
ltlt num1 ltlt " is greater than or equal to "
ltlt num2 ltlt endl return 0 // indicate
that program ended successfully
32
Result Enter two integers, and I will tell you
the relationships they satisfy 3 7 3 is not
equal to 7 3 is less than 7 3 is less than or
equal to 7
33
Introduction

• Header files and namespaces

includeltiostream.hgt or includeltiostreamgt using
namespace std using namespace std then the
built-in object should be used like stdcoutltlt"I
am learning C now"gt using namescape
statistics1 your own class
library
34
Introduction

• Procedural Programming
• action-oriented
• functions are grouped to form a program
• data are provided, in order to perform a
  function, or the data are generated from a
  function

35
Introduction
36
Introduction

• Object-Oriented Programming
• Vision of objects in cataloging or classification
• Object data (attributes) and functions
  (behaviors)
• independence of each object (hiding)
• interface communication between objects
• data oriented through whole program
• main focus is on creating classes which contain
  data member and function member

37
Introduction

• Object-Oriented Programming (cont.)
• objects are declared based on class type
• and program directly makes objects "alive" or in
  action

38
Introduction
39
Introduction

• Why we introduce OOP
• classified data close to real world
• more module and more scalable
• easy to implement
• large available class libraries can be used to
  reused
• You will love OOP for sure