c++ Programming in DS

7/27/2019 c++ Programming in DS

1/30

2003 Prentice Hall, Inc. All rights reserved.

1

Introduction to C++ Programming

OutlineHistory of C and C++C++ Standard LibraryObject TechnologyBasics of a Typical C++ Environment

General Notes About C++ and This BookIntroduction to C++ ProgrammingA Simple Program: Printing a Line of TextAnother Simple Program: Adding Two IntegersArithmeticDecision Making: Equality and Relational Operators

Thinking About Objects: Introduction to Object Technology


2/30


2

History of C and C++

History of C Evolved from two other programming languages

BCPL and B Typeless languages

Dennis Ritchie (Bell Laboratories) Added data typing, other features Development language of UNIX Hardware independent

Portable programs

1989: ANSI standard 1990: ANSI and ISO standard published

ANSI/ISO 9899: 1990


3/30


3

History of C and C++

History of C++ Extension of C Early 1980s: Bjarne Stroustrup (Bell Laboratories) Spruces up C

Provides capabilities for object-oriented programming Objects: reusable software components

Model items in real world Object-oriented programs

Easy to understand, correct and modify

Hybrid language C-like style Object-oriented style Both


4/30


4

C++ Standard Library

C++ programs Built from pieces called classes and functions C++ standard library

Rich collections of existing classes and functions

Building block approach to creating programs Software reuse


5/30


5

Object Technology

Objects Reusable software components that model real world items Meaningful software units

Date objects, time objects, paycheck objects, invoice objects,audio objects, video objects, file objects, record objects, etc.

Any noun can be represented as an object

More understandable, better organized and easier to maintainthan procedural programming

Favor modularity Software reuse

Libraries MFC (Microsoft Foundation Classes) Rogue Wave


6/30


6

Basics of a Typical C++ Environment

C++ systems Program-development environment Language C++ Standard Library


7/30 2003 Prentice Hall, Inc. All rights reserved.

7


Phases of C++ Programs:1. Edit

2. Preprocess

3. Compile

4. Link

5. Load6. Execute

Loader

PrimaryMemory

Program is created inthe editor and stored

on disk.Preprocessor programprocesses the code.

Loader puts programin memory.

CPU takes eachinstruction andexecutes it, possiblystoring new datavalues as the programexecutes.

Compiler Compiler createsobject code and storesit on disk.

Linker links the object

code with the libraries,creates a.out andstores it on disk

Editor

Preprocessor

Linker

CPU

PrimaryMemory

.

.

.

.

.

.

.

.

.

.

.

.

Disk

Disk

Disk

Disk

Disk



8


Input/output cin Standard input stream Normally keyboard

cout Standard output stream

Normally computer screen cerr

Standard error stream Display error messages



9

General Notes About C++and This Book

Book geared toward novice programmers Stress programming clarity C and C++ are portable languages

Portability C and C++ programs can run on many different computers

Compatibility Many features of current versions of C++ not compatible

with older implementations



10

Introduction to C++ Programming

C++ language Facilitates structured and disciplined approach to computer program design

Structured programming

Object-oriented programming



11

A Simple Program:Printing a Line of Text

Comments Document programs Improve program readability Ignored by compiler

Single-line comment Begin with //

Preprocessor directives Processed by preprocessor before compiling

Begin with #


12/30

2003 Prentice Hall, Inc.All rights reserved.

Outline12

fig01_02.cpp(1 of 1)

fig01_02.cppoutput (1 of 1)

1 // Fig. 1.2: fig01_02.cpp2 // A first program in C++.3 #include 45 // function main begins program execution6 int main()

7 {8 std::cout



13


Standard output stream object std::cout Connected to screen



14


Escape Sequence Description

\n Newline. Position the screen cursor to the beginning of the next line.

\t Horizontal tab. Move the screen cursor to the nexttab stop.

\r Carriage return. Position the screen cursor to the beginning of the current line; do not advance to thenext line.

\a Alert. Sound the system bell.\\

Backslash. Used to print a backslash character.\" Double quote. Used to print a double quotecharacter.


15/30


Outline15



1 // Fig. 1.4: fig01_04.cpp2 // Printing a line with multiple statements.3 #include 45 // function main begins program execution6 int main()

7 {8 std::cout


16/30


Outline16



1 // Fig. 1.5: fig01_05.cpp2 // Printing multiple lines with a single statement3 #include 45 // function main begins program execution6 int main()

7 {8 std::cout



17

Another Simple Program:Adding Two Integers

Variables Location in memory where value can be stored Common data types

int - integer numbers

char - characters double - floating point numbers Declare variables with name and data type before use

int integer1;

int integer2;int sum;

Can declare several variables of same type in one declaration Comma-separated list

int intege r1 , integer2, sum;

18



18


Variables Variable names Valid identifier

Series of characters (letters, digits, underscores) Cannot begin with digit Case sensitive

19



19


Input stream object >> (stream extraction operator) Used with std::cin Waits for user to input value, then press Enter (Return) key Stores value in variable to right of operator

Converts value to variable data type

= (assignment operator) Assigns value to variable Binary operator (two operands) Example:

sum = variable1 + variable2;

20


20/30


Outline20


1 // Fig. 1.6: fig01_06.cpp2 // Addition program.3 #include 45 // function main begins program execution6 int main()

7 {8 int integer1; // first number to be input by user9 int integer2; // second number to be input by user10 int sum; // variable in which sum will be stored 1112 std::cout > integer1; // read an integer1415 std::cout > integer2; // read an integer1718 sum = integer1 + integer2; // assign result to sum 1920 std::cout


21/30


Outline21


Enter first integer45Enter second integer72Sum is 117

22


22/30


22

Arithmetic

Arithmetic calculations * Multiplication

/ Division Integer division truncates remainder

7 / 5 evaluates to 1 %

Modulus operator returns remainder 7 % 5 evaluates to 2

23


23/30


23

Arithmetic

Rules of operator precedence Operators in parentheses evaluated first Nested/embedded parentheses

Operators in innermost pair first

Multiplication, division, modulus applied next Operators applied from left to right

Addition, subtraction applied last Operators applied from left to rightOperator(s) Operation(s) Order of evaluation (precedence)

() Parentheses Evaluated first. If the parentheses are nested, the

expression in the innermost pair is evaluated first. If there are several pairs of parentheses on the same level(i.e., not nes ted), they are evaluated left to right.

* , / , or % Multiplication DivisionModulus

Evaluated second. If there are several, they reevaluated left to right.

+ or - AdditionSubtraction

Evaluated last. If there are several, they areevaluated left to ri ght.

24


24/30


24

Decision Making: Equality andRelational Operators

if structure Make decision based on truth or falsity of condition

If condition met, body executed Else, body not executed

Equality and relational operators Equality operators

Same level of precedence

Relational operators

Same level of precedence Associate left to right

25


25/30


25


Standard algebraicequality operator orrelational operator

C++ equalityor relationaloperator

Exampleof C++condition

Meaning of C++ condition

Relational operators

> > x > y x is greater than y

< < x < y x is less than y

>= x >= y x is greater than or equal to y


26/30


26


using statements Eliminate use of std:: prefix Write cout instead of std::cout

27


27/30


Outline27


1 // Fig. : fig01_14.cpp2 // Using if statements, relational3 // operators, and equality operators.4 #include 56 using std::cout; // program uses cout

7 using std::cin; // program uses cin8 using std::endl; // program uses endl910 // function main begins program execution11 int main()12 {13 int num1; // first number to be read from user14 int num2; // second number to be read from user1516 cout num1 >> num2; // read two integers1920 if ( num1 == num2 )21 cout


28/30


Outline28



26 if ( num1 < num2 )27 cout


29/30


Outline29


Enter two integers, and I will tell youthe relationships they satisfy: 7 77 is equal to 77 is less than or equal to 77 is greater than or equal to 7

301 26 Thi ki Ab t Obj t


30/30

301.26 Thinking About Objects:Introduction to Object Technology

and the Unified Modeling Language

Object oriented programming (OOP) Model real-world objects with software counterparts Attributes (state) - properties of objects

Size, shape, color, weight, etc.

Behaviors (operations) - actions A ball rolls, bounces, inflates and deflates Objects can perform actions as well

Inheritance New classes of objects absorb characteristics from existing classes

Objects Encapsulate data and functions Information hiding

Communicate across well-defined interfaces

Documents

c++ Programming in DS