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Fortran Algol 68 C C++ C#

Cobol

Eiffel

JavaAda 95PL/I Pascal

ElementaryProcedural

AdvancedProcedural

SpecialProcedural

ObjectOriented

AdvancedObject

Oriented

Ada 83

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WhatisProgramming?

Take

Aproblem

Asetofdata

Asetoffunctions

Apply to tosolvethe

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C++isanobject-orientedprogramming

(OOP)languagethatisviewedbymany

asthebestlanguageforcreatinglarge-

scaleapplications.

C++isamultiparadigmlanguage.

C++isanobjectdrivenlanguage.

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C++(pronouncedseeplusplus)was

developedbyBjarneStroustrupatBell

Labsin1979.

CombinationofSimula67andc

CWithclasses

In1983,thenamewaschangedtoC++.

C++isanextendedversionofC. C++isasupersetofC.

AlltheconceptsofCareapplicabletoC++

also.

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Differenceb/wCandC++

C

CProcedureOriented

Cdoesnothaveanyclassesorobjects.

Cinput/outputisbasedonlibraryandthe

processesarecarriedoutbyincludingfunctions.

C++

ObjectOriented

ItsupportsClassesandObjects

C++i/oismadethrough

consolecommandscinandcout.

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Differenceb/wCandC++

Cfunctionsdonot

supportoverloading.

Cdoesnotsupportnewordeletecommands.

Chasatopdown

approach.

Chaspredefineddata

types.

C++supportsOverloading.

Newkeywordisusedtocreateanobjectforaclass.

C++hasabottomup

approach.

In c++, User can createsits own datatype usingclass.

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Variablesarelikesmallblackboards

Wecanwriteanumberonthem

Wecanchangethenumber

Wecanerasethenumber

C++variablesarenamesfor

memorylocations

Wecanwriteavalueinthem

Wecanchangethevaluestoredthere

Wecannoterasethememorylocation

Somevalueisalwaysthere

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Variables names are called identifiers Choosing variable names

Use meaningful names that represent

data to be stored First character must be

a letter

the underscore character

Remaining characters must be letters

numbers

underscore character

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Keywords(alsocalledreserved

words)

AreusedbytheC++language

Mustbeusedastheyaredefinedin

theprogramminglanguage

Cannotbeusedasidentifiers

Keywordisanessentialpartofa

languagedefinition.

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C constants can be divided into twomajor categories

Primary Constants

Secondary ConstantsC Constants

Primary Constants Secondary constants

Integer Constant

Real Constant

Character Constant

Array, Pointer

Structure, Union

enum

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Anintegerconstantmusthaveatleastone

digit

Itmustnothaveadecimalpoint

Itcouldbeeitherpositiveornegative

Ifnosignprecedesanintegerconstant,itis

assumedtobepositive

ex.,123,-321,+78 Nocommasorblanksareallowedwithinan

integerconstant

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Realconstants(RC)musthaveatleastonedigit

Itmusthaveadecimalpoint

Itcouldbeeitherpositiveornegative

Defaultsignispositive

NocommasorblankareallowedwithinaRC

Ex.,0.0083,-0.75,+247.0

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ASinglecharacterconstantiseithera

singlealphabet,asingledigitora

singlespecialsymbolenclosedwithinsinglequotes

Themaximumlengthofacharacter

constantcanbe1character Ega,1,5,=(Valid)

asd,12(Invalid)

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Itisasequenceofcharacters

enclosedindoublequotes

Charactersmaybeletters,numbers,

specialcharactersenclosedindouble

quotes.

Eg.,Hello!1987?...!X

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ThemostcommonlyusedDataTypesinC++

programminglanguage:

shortint

int longint

float

double

longdouble char

bool

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Beforeuse,variablesmustbedeclared

Declarationsyntax:

,

, . . . ;

Tellsthecompilerthetypeof

datatostore

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DeclaringVariables

Examples:intnumber_of_students;doubleweight;

isanabbreviationforinteger.

couldstore3,102,3211,-456,etc. number_of_studentsisof integer

representsnumberswithafractionalcomponent

couldstore1.34,4.0,-345.6,etc. Weightisof double

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Declaringavariabledoesnotgiveitavalue Givingavariableavalueinthe

declarationis thevariable Eg:int age = 5;

Givingavaluetothedeclaredvariableis thevariable Eg:int age;

age = 5;

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Include files

Function subprogram

Main function

Global variable and

function declaration

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/* A first C++ Program*/

#include

int main()

{

cout

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Editor DiskPhase 1

Program edited inEditor and stored

on disk

Preprocessor DiskPhase 2

Preprocessor

program processesthe code

CompilerDisk

Phase 3

Creates object code

and stores on disk

Linker DiskPhase 4

Links object code

with libraries and

stores on disk

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LoaderPhase 5

Puts program in

memory

Primary memory

CPUPhase 6

Takes each instruction

and executes it storingnew data values

Primary memory

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Input and Output

A isasequenceofdata

Typicallyintheformofcharactersornumbers

Aninputstreamisdatafortheprogramtouse Typicallyoriginates

atthekeyboard

atafile

Anoutputstreamistheprogramsoutput

Destinationistypically

themonitor

afile

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cout is an output stream sending data to the monitor The insertion operator"

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cinisaninputstreambringingdatafromthe

keyboard

Theextractionoperator(>>)getsdatatobeused

Example: cout

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Multipledataitemsareseparatedbyspaces

Dataisnotreaduntiltheenterkeyis

pressed Example: cin >> v1 >> v2 >> v3;

Requiresthreespaceseparatedvalues

Usermighttype344512

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Prompttheuserforinputthatisdesired

coutstatementsprovideinstructions

cout > age;

Displayingtheoutputwhatwasread

cout

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Commentshouldbeenclosedbetween

SingleLineCommentis

Itisusedtoincreasethereadabilityoftheprogram.

Anynumberofcommentscanbegivenatanyplaceinthe

program.

Commentcannotbenested.

Itcanbesplitovermorethanoneline

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\n newline

\t tab

\r carriagereturn

\a alert

\\ backslash

\ doublequote \? QuestionMark

\ QuotationMark

\0 Null

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An operator is asymbol(Eg:+,-,*,/)that directs the computer to performcertain mathematical or logical

manipulations and is usually used tomanipulate data and variables.

Eg: a + b

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1. Arithmetic operators

2. Relational operators

3. Logical operators

4. Assignment operators

5. Increment and decrement operators

6. Conditional operators

7. Bitwise operators

8. Special operators

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C++ operation Algebraic C++

Addition(+) f+7 f+7

Subtraction (-) p-c p-c

Multiplication(*) bm b*m

Division(/) x/y, x , x y x/y

Modulus(%) r mod s r%s

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Highest to lowest

()

*, /, %

+, -

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a(b+c)+c(d+e)

C:

a * ( b + c ) + c * ( d + e ) ;

Precedence:

3 1 5 4 2

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/* Program using Arithmetic operator */

#include

#include

void main(){

int a=5,b=6; // Initializing variables

int c;

clrscr(); // To clear the screen

c=a+b; // + operator

cout

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Operator Meaning

< Is less than

Is greater than

>= Is greater than or equal to

== Equal to

!= Not equal to

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Operator Meaning

&& Logical AND

|| Logical OR

! Logical NOT

Logical expressions are a compound relationalexpressions

-An expression that combines two ormore relational expressions

Eg: if (a==b && b==c)

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Syntax:

v op = exp;

Where v = variable,

op = shorthand assignment operator

exp = expression

Ex:x=x+3

x+=3

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Simple assignment operator Shorthand operator

a = a+1 a + =1

a = a-1 a - =1

a = a* (m+n) a * = m+n

a = a / (m+n) a / = m+n

a = a %b a %=b

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1. Increment ++

2. Decrement --

The ++ operator adds a value 1 to the operand

The operatorsubtracts 1 from the operand

++a / --a => pre increment / decrement

a++ / a-- => post increment / decrement

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Let the value of a =5 and b=++a then

a = b =6

Let the value of a = 5 and b=a++ then

a =5 but b=6

i.e.:

1. a prefix operator first adds 1 to the operand and thenthe result is assignedto the variable on the left

2. a postfix operator first assigns the value to thevariable on left and thenincrements the operand.

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Syntax:

exp1 ? exp2 : exp3

Where exp1,exp2 and exp3 are expressions

Working of the ? : Operator:Exp1 is evaluated first, if it is nonzero(1/true) then theexpression2 is evaluated and this becomes the value of theexpression,

If exp1 is false(0/zero) exp3 is evaluated and its value

becomes the value of the expression

Eg: m=2;

n=3;

r=(m>n) ? m : n; // Here r = n

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/* Program using Conditional operator */

#include

#include

void main(){

int a,b,c; // Declaring variables

a=5; // Assigning values

b=6;

clrscr(); // To clear the screen

c=(a>b)?a:b; // Conditional operator

cout

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Operator Meaning

& Bitwise AND

| Bitwise OR

^ Bitwise exclusive OR

> Shift right

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/* Program using bitwise operators */

#include

#include

void main()

{

clrscr();

int a=5,b=6; // a = 0101 , b = 0110int c;

c=a&b;

cout

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c=a|b;

cout