PPS Unit-1.pdf

software

1. 1
Programming For Problem Solving
I B.TechI Semester
BY
Mrs. PavaniB
Assistant Professor
Computer Science and Engineering
MRCET

2. 2
“Unit-I”
IntroductiontoComputing–ComputerSystems,Computing
Environments,ComputerLanguages,Algorithmsand
Flowcharts,StepsforCreatingandRunningprograms.
IntroductiontoC–HistoryofC,FeaturesofC,StructureofC
Program,CharacterSet,CTokens-keywords,Identifiers,
Constants,Datatypes,Variables.Operators,Expressions,
PrecedenceandAssociativity,ExpressionEvaluation,Type
conversion,typedef,enum
ControlStructures:SelectionStatements(DecisionMaking)–if
andswitchstatements,RepetitionStatements(Loops)-while,
for,do-whilestatements,UnconditionalStatements–break,
continue,goto,Commandlinearguments.

3. Introduction to Computer System
AComputerisanelectronicdevicethatreceivesinput,storesor
processestheinputasperuserinstructionsandprovidesoutputin
desiredformat.
Input-Process-OutputModel
Computerinputiscalleddataandtheoutputobtainedafterprocessing
it,basedonuser’sinstructionsiscalledinformation.

4. Introduction to Computer System
Acomputerisasystemmadeoftwomajorcomponents.
1.Software
2.Hardware
Hardware:Physicalpartsofcomputerthatwecantouch
calledashardware.
i.e.Monitor,CPU,Keyboard,Mouse,etc.
Software:Itisasetofinstruction/programthattellsthe
computerwhattodo.
i.e.OperatingSystem,MSOffice,etc.

5. Introduction to Computer System
ComputerHardware:Thehardwarecomponentsofthe
computersystemisdividedinto4majorcomponents
1.InputDevices
2.OutputDevices
3.CPU(CentralProcessingUnit)
4.StorageDevices

6. 6
Components of a Computer System
Input and Output Devices of a Computer System

7. Components of a Computer System
TheCentralProcessingUnit(CPU)isresponsibleforexecuting
instructionssuchasarithmeticcalculations,comparisonsamongdata,
andmovementofdatainsidethesystem.

8. Components of a Computer System

9. Computer Software

10. Relationship between System and Application Software is shown below

11. Compiler
Acompilerisacomputerprogramthattranslatescomputercode
writteninoneprogramminglanguage(thesourcelanguage)into
anotherlanguage(thetargetlanguage).

12. Computing Environments
Intheearlydaysofcomputer,thereisonlyoneenvironment:the
mainframecomputerhiddeninacentralcomputingdepartment.
Withtheadventofminicomputersandpersonalcomputer,the
environmentchanged,resultingincomputersonvirtuallyevery
desktop
1.Personal Computing Environment
2.Time-Sharing Environment
3.Client/Server Environment
4.Distributed Computing

13. Computing Environments
Personal Computing Environment
Inthepersonalcomputingenvironment,thereisasingle
computersystem.Allthesystemprocessesareavailableonthe
computerandexecutedthere.Thedifferentdevicesthatconstitute
apersonalcomputingenvironmentarelaptops,mobiles,printers,
computersystems,scannersetc.
Time Sharing Computing Environment
Thetimesharingcomputingenvironmentallowsmultipleusersto
sharethesystemsimultaneously.Eachuserisprovidedatime
sliceandtheprocessorswitchesrapidlyamongtheusers
accordingtoit.Becauseofthis,eachuserbelievesthattheyare
theonlyonesusingthesystem.

14. Fig : Time Sharing Computing Environment

15. Client Server Computing Environment
Inclientservercomputing,theclientrequestsaresourceandthe
serverprovidesthatresource.Aservermayservemultipleclients
atthesametimewhileaclientisincontactwithonlyoneserver.
Boththeclientandserverusuallycommunicateviaacomputer
networkbutsometimestheymayresideinthesamesystem.

16. Distributed Computing Environment
Adistributedcomputingenvironmentcontainsmultiplenodesthat
arephysicallyseparatebutlinkedtogetherusingthenetwork.All
thenodesinthissystemcommunicatewitheachotherandhandle
processesintandem.Eachofthesenodescontainsasmallpartof
thedistributedoperatingsystemsoftware.

17. Computer Languages

18. Machine Languages/Low Level Languages
Intheearliestdaysofcomputers,theonlyprogramming
languageavailableweremachinelanguages.Eachcomputer
haditsownmachinelanguage,whichwasmadeofstreamsof
0sand1s.
The only language
understood by a
computer is
machine language.

19. Symbolic Languages
•TheSymboliclanguagesusessymbolsormnemonicsto
representthevariousmachinelanguageinstructionsbut
symboliclanguagewasnotunderstoodbythecomputersoit
mustbetranslatedtothemachinelanguage..
•Aspecialprogramcalledassemblerusedtoconvertinto
machinelanguage.Symboliclanguagesareknownas
Assemblylanguages..
Example
1.mov eax, 10
2.mov ecx, 20
3.add eax, ecx

20. High-level Languages
•Althoughassemblylanguagesgreatlyimprovedprogramming
efficiency,theystillrequiredprogrammerstoconcentrateon
thehardwaretheywereusing.
•So,Highlevellanguagesaredesignedtorelivethe
programmerfromthedetailsoftheassemblylanguage.These
areportabletomanydifferentcomputers,allowingthe
programmertoconcentrateontheapplicationprogram.
•Overtheyears,variouslanguages,mostnotably
BASIC,COBAL,pascal,Ada,C,C++andjavaweredeveloped
•High-levellanguagesshouldbeconvertedintomachine
language.Thisprocessiscalledcompilation.

21. Algorithm
•Analgorithmisastepbystepprocesstosolveaproblemusing
afinitenumberofsteps.Algorithmsareusedinmathematical
computingetctocarryoutcalculationsordataprocessing.
•Thealgorithmisdevelopedusingpseudocodewhichcanthenbe
convertedtoacprogram
•Pseudocode:Itisanartificialandinformallanguagethathelps
programmerstodevelopalgorithm.Pseudocodeissimilarto
everydayenglish,itisconvenientanduser-friendly.
•Pseudocodeprogramsarenotexecutedoncomputersbutthey
areusedindevelopingalgorithms

22. Allthealgorithmsmustsatisfyfollowingproperties
PropertiesofAlgorithms
•Input–thealgorithmmustacceptzeroormoreinputs
•Output-mustproduceatleastoneoutput
•Definiteness-Eachinstructionisclearandunambiguous.
•Finiteness-Analgorithmshouldterminateafterafinite
numberofsteps.Itshouldnotenterintoaninfiniteloop
•Effectiveness–Eachoperationmustbesimpleandshould
completeinafinitetime

23. Algorithm : Addition of two numbers
Step 1: Start
Step 2: Declare variables num1, num2 and sum.
Step 3: Read values into num1 and num2.
Step 4: sum = num1+num2
Step 5: print sum
Step 6: Stop

24. Algorithm : Area of circle
Step 1: Start
Step 2: Declare variables radius and Area
Step 3: Read value into radius
Step 4: Area = 3.14*radius*radius
Step 5: print Area
Step 6: Stop

25. Algorithm : Largest among 3 numbers
Step 1: Start
Step 2: Declare variables a,band c.
Step 3: Read variables a,band c.
Step 4: If a > b
If a > c
Display a is the largest number.
Else
Display c is the largest number.
Else
If b > c
Display b is the largest number.
Else
Display c is the greatest number.
Step 5: Stop

26. Algorithm to print "n" natural numbers
Step 1: Start
Step 2: Declare n, i
Step 3: Assign i=1
Step 4: Read value into n
Step 5: Repeat step 5.1 and 5.2 until i<=n
5.1 Print i
5.2 Compute i=i+1
Step 7: Stop

27. Algorithm to sum "n" natural numbers
Step 1: Start
Step 2: Declare variables n, sum and i.
Step 3: Initialize variables or Assign
sum = 0
i = 1
Step 4: Read value into n
Step 5: Repeat 5.1 and 5.2 until i <= n
5.1 : sum = sum+i
5.2 : i = i+1
Step 6: Display sum
Step 7: Stop

28. Flowchart
•Aflowchartisagraphicalrepresentationofanalgorithm.
Flowchartsaredrawnusingcertainspecial-purposesymbols
suchasrectangles,diamonds,ovals,andsmallcirclesasshown
below.
•Thesesymbolsareconnectedbyarrowscalledflowlines.Like
pseudocode,flowchartisusefulfordevelopingand
representingalgorithms.

30. Flowchart : Addition of two numbers
Step 1: Start
Step 2: Input/Read Number1 and Number2.
Step 3: Sum = Number1+Number2
Step 4: Print Sum
Step 5: Stop

31. Flowchart : Area of circle
Step 1: Start
Step 2: Read value into Radius
Step 3: Area = 3.14*Radius*Radius
Step 4: Display Area
Step 5: Stop

32. Flowchart : Largest among two numbers

33. Flowchart : Largest among three numbers
Read A,B,C
Print B is
largest
Print C is
largest
Print A is
largest
Start
Is
A>B
Is
A>C
Is
B>C
YesNo
No No
YesYes
Stop

34. Start
Assign i=1
Read n
Is
i<=n
Compute i=i+1
Stop
No
Yes
Flowchart for printing ‘n’ natural numbers
Print i

35. Start
Assign
Sum=0,i=1
Read n
Is
i<=n
Sum=Sum+i
Compute i=i+1
Stop
No
Yes
Sum of ‘n’ natural numbers
Print Sum

36. Creating, Compiling and Executing a Program

37. Creating, Compiling and Executing a Program
Syntax to create a file in linuxoperating system
$ geditfilename.c
Example :
$ geditadd.c
How to Compile a Program?
$ gccadd.c
How to run the program?
$ ./a.out

40. Features
•Itwasmainlydevelopedasasystemprogramminglanguageto
writeanoperatingsystem.
•ThemainfeaturesofClanguageinclude
•Low-levelaccesstomemory
•Asimplesetofkeywords
•Cleanstyle
•Easy to learn
•Structured language
•It produces efficient programs.
•ThesefeaturesmakeClanguagesuitableforsystemprogramming
likeanoperatingsystemorcompilerdevelopment.

41. Structure of a C Program

42. Documentationsection:Toenhancethereadabilityofthe
program,programmerscanprovidecommentsaboutthe
programinthissection.Commentscanbeusedanywherein
theprogrambuttoomanycommentsareavoided.
Example
/*Thisisaexampletochecklargestnumber*/
Headerfile/linksection:Cprogramdependsuponsome
headerfilesforfunctiondefinitionthatareusedinprogram.
Eachheaderfilebydefaultisextendedwith.h.Thefileshould
beincludedusing#includedirective.
#include <stdio.h>
or
#include “stdio.h”

43. Globaldeclarationsection:Thissectiondeclaressome
variablesthatareusedinmorethanonefunction.These
variablesareknownasglobalvariables.Thesemustbedeclared
outsideofallthefunctions.
Mainprogramsection:EveryprogramwritteninClanguage
mustcontainmain()function.Theexecutionoftheprogram
alwaysbeginswiththefunctionmain().
Theprogramexecutionstartswiththeopeningbrace({)and
endswiththeclosingbrace(}).Betweenthesetwobracesthe
programmershoulddeclarethedeclarationpartandthe
executablepart.

44. DeclarationPart:Thedeclarationpartdeclarestheentire
variablesthatareusedinexecutablepart.Theinitializationof
variablesalsodonehere.Theinitializationmeansproviding
theinitialvaluetothevariables
ExecutablePart:Thispartcontainsthestatementsfollowing
thedeclarationofthevariables.Thispartcontainsasetof
statements.Thesestatementsareenclosedbetweenthebraces.
User-definedfunction:Thefunctiondefinedbytheuseris
calleduserdefinedfunction.Thesefunctionsaregenerally
definedafterthemain()function.Theycanalsobedefined
beforemain()function.Thisportioninnotcompulsorynow.

46. /* Program to add two numbers */
#include<stdio.h> /* header file section */
intmain()
{
inta=10,b=20,c; //declaration part
c=a+b; //Executable part
printf("%d",c);
}
OUTPUT : 30
Note : initializing values in program itself

47. /* Program to add two numbers */
#include<stdio.h>
intmain()
{
inta,b,sum;
printf(“Enter any two values:”);
scanf(“%d %d”,&a,&b);
sum=a+b;
printf("%d",sum);
return 0;
}
OUTPUT : Enter any two values:15 30
45
Note : Taking input through keyboard

48. C Tokens
TOKENis the smallest
individual unit in a 'C'
program.

49. Keywords
Keywordsarethosewordswhosemeaningisalreadydefinedby
Compiler.Thereare32KeywordsinC.

50. Identifiers
Identifiersarethenamesgiventovariables,functionsandarrays
Eachidentifiedvariablestoredinauniqueaddress.Theseidentifierare
definedagainstasetofrules.
RulesforanIdentifier
•Thefirstcharacterofanidentifiercanonlycontainalphabet(a-z,
A-Z)orunderscore(_).
•IdentifiersarealsocasesensitiveinC.Forexamplenameand
NamearetwodifferentidentifiersinC.
•KeywordsarenotallowedtobeusedasIdentifiers.
•Nospecialcharacters,suchassemicolon,period,whitespaces,slash
orcommaarepermittedtobeusedinorasIdentifier.
•Anidentifiershouldnotcontainanywhitespaces.

51. Variables
Avariableisanameofthememorylocation.Itisusedtostoredata.
Itsvaluecanbechanged,anditcanbereusedmanytimes.
Syntax:
Data_typevariable_list;
Example:
inta;
floatb;
charc;
Here,a,b,carevariables.
Theint,float,chararethedatatypes.

52. Datatypes
Adatatypespecifiesthetypeofdatathatavariablecanstoresuchas
integer,floating,character,etc.

53. CharacterDataType:
•
•
•
•
Characterdatatypeallows avariabletostoreonly onecharacter.
Sizeofcharacterdatatypeis 1 byte(8bits).
“char”keywordis used to refercharacterdata type.
Forexample,‘A’canbestoredusingchardatatype.Youcan’tstore
morethan onecharacterusingchardata type.
Formatspecifier orcontrolstringis %c
Rangeforsignedchar-128 to 127 and unsigned charis0 to 255.
•
•
•Example:chargender=‘F’;
Datatypes

54. IntegerDataType:
•Integerdata typeallows avariable to storenumeric values.
•“int” keywordisusedtoreferintegerdatatype.
•
•
Thestoragesizeofintdatatypeis2
Itvariesdependupontheprocessor
areusing16bitprocessor,2byte
allocatedforintdatatype.
or4 or8 byte.
intheCPUthatweuse.Ifwe
(16bit)ofmemorywillbe
•Likewise,4byte(32bit)ofmemoryfor32bitprocessorand
8byte(64bit)ofmemoryfor64bitprocessorisallocatedforint
datatype.
Datatypes

55. •int(2byte)canstorevalues
int.0 to 65535 forunsigned
from-32,768to+32,767forsigned
int.
•int(4byte) canstorevaluesfrom-2,147,483,648to
+2,147,483,647forsignedint.0to4,29,49,67,295forunsigned
int.
Ifyouwanttousetheintegervaluethatcrossestheabovelimit,
youcangofor“longint”and“longlongint”forwhichthe
limitsareveryhigh.
•
Note:
•Wecan’t storedecimal values using intdatatype.

56. Datatypes
Float and double
float and double are used to hold real numbers(decimal values).
For Example : float a=33.6;
Type Storage size Value range PrecisionControl
String
float 4 bytes(32 bits)1.2E-38 to 3.4E+38 6 decimal
places
%f
double 8 bytes(64 bits)3E-308 to 1.7E+30815 decimal
places
%lf
long double10 bytes(80 bits)3.4E-4932 to 1.1E+493219 decimal
places
%Lf

57. MODIFIERSINC LANGUAGE:
•Modifiersareprefixedwith basicdata typestomodify
(eitherincreaseordecrease)theamountofstoragespace
allocatedtoavariable.
Forexample,storagespaceforintdatatypeis4bytefor32
bitprocessor.Wecanincreasetherangebyusinglongint
whichis8byte.Wecandecreasetherangebyusingshort
intwhichis2byte.
•
•Thereare5 modifiersavailablein C language. They are,
•
•
•
•
•
short
long
signed
unsigned
long long

58. -2
(n-1)to 2
(n-1)-1Tocalculaterangefor charorintor long
Herenrepresentsnumberofbits

59. Syntax and Logical Errors
Syntaxerrorsarealsoknownasthecompilationerrorsasthey
occurredatthecompilationtime.
Theseerrorsaremainlyoccurredduetothemistakeswhiletypingor
donotfollowthesyntaxofthespecifiedprogramminglanguage.
Example:
Ifwewanttodeclarethevariableoftypeinteger,
inta;//thisisthecorrectform
Inta;//thisisanincorrectform.
Commonlyoccurredsyntaxerrorsare:
Ifwemisstheparenthesis(})whilewritingthecode.
Displayingthevalueofavariablewithoutitsdeclaration.
Ifwemissthesemicolon(;)attheendofthestatement.

60. Syntax and Logical Errors
Thelogicalerrorisanerrorthatleadstoanundesiredoutput.These
errorsproducetheincorrectoutput.Theoccurrenceoftheseerrors
mainlydependsuponthelogicalthinkingofthedeveloper.
Example.
Manydifferenttypesofprogrammingmistakescancauselogic
errors.Forexample,assigningavaluetothewrongvariablemay
causeaseriesofunexpectedprogramerrors.Multiplyingtwo
numbersinsteadofaddingthemtogethermayalsoproduce
unwantedresults.

61. Constants
Aconstantisavaluethatcan'tbechangedintheprogram,for
example:10,20,'a',3.4,"cprogramming"etc.

62. BACKSLASHCHARACTER CONSTANTSINC:
•Therearesomecharacterswhichhavespecialmeaning
inClanguage.
•Theyshouldbeprecededbybackslashsymboltomake
useofspecialfunctionofthem.
•Givenbelowisthelistofspecialcharactersandtheir
purpose.
\n New line
\t Horizontal tab
\v Vertical tab

63. Variables can be declared as constant using the const keyword
#include <stdio.h>
intmain()
{
inta=10;
a=20;
printf("a=%d", a);
return 0;
}
#include <stdio.h>
intmain()
{
const inta=10;
a=20;
printf("%d", a);
return 0;
}
The const keyword
OUTPUT
a=20
OUTPUT
Error

64. 64
Input / Output Functions
printf()function:
Theprintf()functionisusedforoutput.Itprintsthegivenstatement
totheconsole.
Thesyntaxofprintf()functionisgivenbelow:
Theformatstringcanbe%d(integer),%c(character),%s(string),%f
(float)etc.
scanf()function:
Thescanf()functionisusedforinput.Itreadstheinputdatafromthe
console.
scanf("formatspecifier",variable_list);
printf("formatspecifier",variables_list);

65. 65
Input / Output Functions Example
Programtoprintcubeofgivennumber
#include<stdio.h>
intmain()
{
intnumber;
printf("enteranumber:");
scanf("%d",&number);
printf("cubeofnumberis:%d",number*number*number);
return0;
}

66. 66
Operators in C
•Csupportsrichsetofoperators.
•Anoperatorisasymbolthattellsthecompilertoperformcertain
mathematicalorlogicalmanipulations.
•Operatorsareusedinprogramstomanipulatedataandvariables.

67. 67
Operators in C
Types of ‘C’ operators
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

68. 68
Arithmetic Operators
Anarithmeticoperatorperformsmathematicaloperationssuchas
addition,subtractionandmultiplicationonnumericalvalues(constants
andvariables).
Operator Meaning of Operator
+ addition or unary plus
- subtraction or unary minus
* multiplication
/ division
% remainder after division( modulo division)
Note:-Modulardivisionoperator%cannotusedonfloating
pointdata

69. OUTPUT
a+b = 13
a-b = 5
a*b = 36
a/b = 2
Remainder = 1
Example
include <stdio.h>
intmain()
{
inta = 9,b = 4, c;
c = a+b;
printf("a+b = %d \n",c);
c = a-b;
printf("a-b = %d \n",c);
c = a*b;
printf("a*b = %d \n",c);
c = a/b;
printf("a/b = %d \n",c);
c = a%b;
printf("Remainder = %d \n", c);
return 0;
}

70. include <stdio.h>
intmain()
{
inta = 9,b = 4, sum,sub,mul,div,rem;
sum = a+b;
sub = a-b;
mul= a*b;
div = a/b;
rem = a%b;
printf("%d \n",sum);
printf(" %d \n",sub);
printf("%d \n",mul);
printf(“%d\n",div);
printf(“%d \n", rem);
return 0;
}
OUTPUT
13
5
36
2
1

71. include <stdio.h>
intmain()
{
inta = 9,b = 4;
printf(“sum = %d \n",a+b);
printf(“sub = %d \n",a-b);
printf(“mul= %d \n",a*b);
printf(“div = %d \n",a/b);
printf("Remainder = %d \n", a%b);
return 0;
}
OUTPUT
sum = 13
sub = 5
mul= 36
div = 2
Remainder = 1

72. 72
Operators in C
Relational Operators
Relationaloperatorsareusedtofindtherelationbetweentwo
variables.i.e.tocomparethevaluesoftwovariablesinaCprogram.

73. If a=20 b=10
a>b it returns 1 (True)
a<b it returns 0 (False)
a<=b it returns 0 (False)
a>=b it returns 1 (True)
a==b it returns 0 (False)
a!=b it returns 1(True)
If a=10 b=10
a==b it returns 1 (True)
a!=b it returns 0 (False)
Relational Operators with Example

74. 74
OUTPUT
0
0
1
0
1
1
Example
#include<stdio.h>
intmain()
{
inti=7,j=1;
printf(“%d \n”,i==j);
printf(“%d \n”,i<j);
printf(“%d \n”,i>j);
printf(“%d \n”,i<=j);
printf(“%d \n”,i>=j);
printf(“%d \n”,i!=j);
return 0;
}

75. 75
Logical Operators
•Allowaprogramtomakeadecisionbasedonmultipleconditions.
•Logicaloperatorsareusedwhenwewanttotestmorethanonecondition.
•Examplea>b&&a>c

76. 76
5>3 && 5<10 returns 1
8>5 && 8<2 returns 0
8>5 || 8<2 returns 1
!(8>5) returns 0

77. #include<stdio.h>
intmain()
{
printf(“%d \n”,5>3 && 5<10);
printf(“%d \n”,8>5 && 8<2);
printf(“%d \n”,8>5 || 8<2);
printf(“%d \n”,!(8>5));
return 0;
}
output
1
0
1
0

78. 78
Operators in C
Assignment Operators
•Assignment operators are used to assign the result of an
expression to avariable.
•C has a set of ‘shorthand’ assignment
operator:
variable name=expression;
Leftsidemustbeavariablethat
canreceiveavalue
Example
c=a+b;

79. 79
Operatorsin C
Shorthand Assignmentoperators
SimpleAssignment
Operator
ShorthandOperator
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

80. #include<stdio.h>
intmain()
{
inta,b,c;
printf(“Enter any two integer values \n”);
scanf(“%d %d”,&a,&b);
c=a+b;
c+=10;
printf(“ sum=%d”, c);
}
OUTPUT
Enter any two integer values 10 20
Sum=40

81. 81
Increment and Decrement Operators
Incrementoperatorsareusedtoincreasethevalueofthevariable
byoneanddecrementoperatorsareusedtodecreasethevalueof
thevariablebyone.
Syntax:
Increment operator: ++
pre increment : ++var_name;
post increment : var_name++;
Decrement operator: --
pre decrement: ––var_name;
post decrement var_name––;
Example:
Increment operator :++ iandi++ ;
Decrement operator : ––iand i––;

82. Example
NOTE:
Apostfixoperatorfirstassignsthevaluetothevariableonleft
andthenincrementstheoperand.
Ontheanotherhand,Aprefixoperatorfirstadds1tothe
operandandthenresultisassignedtothevariableonleft.
If x=5
a = x++ ; a=5 x=6
a = ++x;a=6 x=6
a = x––; a=5 x=4
a = ––x;a=4 x=4

83. 83
Example
#include<stdio.h>
intmain()
{
inta=1,b=1;
printf(“%d”,++a);
printf(“ %d ”,b++);
printf(“ %d ”,b);
return 0;
}
OUTPUT
2 1 2
#include<stdio.h>
intmain()
{
inta=1,b=1;
printf(“%d”,--a);
printf(“ %d ”,b--);
printf(“ %d ”,b);
return 0;
}
OUTPUT
0 1 0

84. 84
Operators in C

85. #include<stdio.h>
main()
{
inta=9,b=9;
a=b++;
b=a++;
b=++b;
printf("%d%d",a,b);
}
a) 9,9
b) 10,10
c) 9,10
d) 10,9
#include <stdio.h>
main()
{
inta,b;
b = 10;
a = ++b + ++b;
printf("%d%d",a,b);
}
a) 24,12
b) 23,12
c) 23,10
d) 24,10

86. 86
Operators in C
Conditional Operators
•Theconditionalexpressioncanbeusedasshorthandforsomeif-else
statements.Itisaternaryoperator.
•Thisoperatorconsistoftwosymbols:thequestionmark(?)andthe
colon(:).

87. 87
Example
intmain()
{
int a ,b, c;
a =10;
b = (a == 1) ? 20:30;
printf( “ Value of b is %d \n ", b ); // 30
c = (a == 10) ? 20 :30;
printf( “ Value of c is %d \n", c); // 20
return 0;
}

88. Example
intmain()
{
int a =10,b=20;
if(a >b) ? printf(“a is greater”):printf(“b is greater”);
return 0;
}

89. 89
Operators in C
Bitwise Operators
•IntheCprogramminglanguage,operationscanbeperformedona
bitlevelusingbitwiseoperators.
•FollowingarethebitwiseOperators

90. 90
Operators in C
Truth Table

91. 91
Operators in C
ShiftOperator:
LeftShiftOperator(<<):Theleftshiftoperatorwillshift
thebitstowardsleftforthegivennumberoftimes.
inta=2<<1;
printf(“%d”,a);//willprint4
Ifyouleftshiftlike2<<2,thenitwillgivetheresultas8.
Thereforeleftshifting1time,isequaltomultiplyingthe
valueby2.
RightshiftOperator(>>)
Therightshiftoperatorwillshiftthebitstowardsrightfor
thegivennumberoftimes
intb=4>>1
printf(“%d”,b);//willprint2
Rightshifting1time,isequivalenttodividingthevalue
by2.

92. 92
Operators in C
Special Operators
C supports some special operators suchas:
•commaoperator “,” is used to link related expressions together
inta=5,b=6;
•sizeof operator“sizeof()”
•Addressoperator “&”
•pointeroperator “*”
•memberselectionoperator“. and ->”
•Size of operator returns the number of bytes occupied in
memory..theoperand may be variable or constant or data type
qualifier

93. #include<stdio.h>
intmain()
{
inta;
float b;
char c;
double d;
printf("Size of int: %d bytes\n", sizeof(a));
printf("Size of float: %d bytes\n", sizeof(b));
printf("Size of char: %d bytes\n", sizeof(c));
printf("Size of double: %d byte\n", sizeof(d));
return 0;
}
Size of int: 4 bytes
Size of float: 4 bytes
Size of char: 1 bytes
Sizeofdouble:8byte

94. Expressions
Anexpressionisacollectionofoperatorsandoperandsthat
representsaspecificvalue.
Whatisanexpression?
ExpressionTypesinC
IntheCprogramminglanguage,expressionsaredividedinto
THREEtypes.Theyareasfollows...
1.InfixExpression–Example:a+b
2.PostfixExpression–Example:a++
3.PrefixExpression–Example:++a

95. 95
Operator Precedence and Associativity
WhatisOperatorPrecedence?
•Operatorprecedenceisusedtodeterminetheorderofoperators
evaluatedinanexpression.Incprogramminglanguageevery
operatorhasprecedence(priority).
•Whenthereismorethanoneoperatorinanexpression,the
operatorwithhigherprecedenceisevaluatedfirstandthe
operatorwiththeleastprecedenceisevaluatedlast.
What is Operator Associativity?
•Operatorassociativityisusedtodeterminetheorderof
operatorswithequalprecedenceevaluatedinanexpression.
•Inthecprogramminglanguage,whenanexpressioncontains
multipleoperatorswithequalprecedence,weuseassociativity
todeterminetheorderofevaluationofthoseoperators.

96. 96
Operator Precedence and Associativity

100. 100
Expression Evaluation
3

101. 101
Type Conversion
ThetypeconversionprocessinCisbasicallyconvertingonetype
ofdatatypetoothertoperformsomeoperation.
Theconversionisdoneonlybetweenthosedatatypeswhereinthe
conversionispossible
example–chartointandviceversa.
Therearetwotypesofconversions:
1.ImplicitTypeConversion
2.ExplicitTypeConversion
ImplicitTypeConversion
Thistypeofconversionisusuallyperformedbythecompiler
whennecessarywithoutanycommandsbytheuser.Thusitisalso
called"AutomaticTypeConversion".

102. 102
Type Conversion

103. 103
Type Conversion

104. 104
Type Conversion
Example 1
int a = 20;
double b = 20.5;
a + b; -----40.5
Example 2
char ch='a';
int x =13;
x + ch; ------110

105. 105
Type Conversion

106. 106
Type Conversion-Example
#include<stdio.h>
intmain()
{
float a = 4.5;
float b = 4.6;
float c = 4.9;
intresult;
result = (int)a + (int)b + (int)c;
printf("result = %d", result);
return 0;
}
Output : 12
#include<stdio.h>
intmain()
{
float a = 4.5;
float b = 4.6;
float c = 4.9;
float result;
result = a + b + c;
printf("result = %d", result);
return 0;
}
Output : 14.000000

107. 107
typedef
typedefis a keyword used in C language to assign alternative names to
existing datatypes.
Its mostly used with user defined datatypes.
Following is the general syntax for using typedef,
typedef <existing_name> <alias_name>
Example:
#include <stdio.h>
int main()
{
typedefint unit;
unit i,j;
i=10,j=20;
printf("Value of i is :%d",i);
printf("\nValueof j is :%d",j);
return 0;
}

108. Conditional Statements
•ConditionalStatements/Decision-makingstatementsarethe
statementsthatareusedtoverifyagivenconditionanddecide
whetherablockofstatementsgetsexecutedornot,basedonthe
conditionresult.
•Inthecprogramminglanguage,therearetwodecision-making
statementstheyareasfollows.
1.ifstatement
2.switchstatement

109. if statement in C
ifstatementisusedtomakedecisionsbasedonacondition.Theif
statementverifiesthegivenconditionanddecideswhetherablockof
statementsareexecutedornot,basedontheconditionresult.
Inc,ifstatementisclassifiedintofourtypesasfollows...
•Simpleifstatement
•if-elsestatement
•Nestedifstatement
•else-ifladder

110. Simple if statement
Syntax:
if(condition)
{
//Statementstoexecute
ifconditionistrue
}
It is used to decide whether a certain
statement or block of statements will be
executed or not

111. Simple if statement-Example
//CprogramtoillustrateIfstatement
#include<stdio.h>
intmain()
{
inti=10;
if(i>15)
{
printf("10islessthan15");
}
printf("IamNotinif");
}

112. if-else statement
Syntax:
if(condition)
{
//statementblock1
//conditionistrue
}
else
{
//statementblock2
//conditionisfalse
}
if a condition is true it will execute a
statement block 1 and if the condition is
falseit will executes a statement block 2

113. //CprogramtoillustrateIf-elsestatement
#include<stdio.h>
intmain()
{
intn;
printf(“enteranynumber”);
scanf(“%d”,&n);
if(n%2==0)
{
printf(“numberiseven”);
}
else
{
printf(“numberisodd”);
}
return0;
}

114. Nested if-else statement
Syntax:
if(condition1)
{
if(condition2)
{
statement1;
}
else
{
statement2;
}
}
else
{
statement3;
}
Nested ifstatements means anifstatement inside anotherifstatement.

115. Nested if-else statement-Example
#include<stdio.h>
voidmain()
{
inta,b,c;
printf("Enter3numbers...");
scanf("%d%d%d",&a,&b,&c);
if(a>b)
{
if(a>c)
{
printf("aisthegreatest");
}
else
{
printf("cisthegreatest");
}
}
else
{
if(b>c)
{
printf("bisthegreatest");
}
else
{
printf("cisthegreatest");
}
}
}

116. else-if ladder statement
Syntax:
if(Condition1)
{
statementblock1;
}
elseif(Condition2)
{
statementblock2;
}
elseif(Condition3)
{
statementblock3;
}
….
else
defaultstatement;

117. #include<stdio.h>
int main()
{
int s1,s2,s3,s4,s5,sum,avg;
printf("Enter marks of 5 subjects each out of 100 \n ");
scanf("%d %d %d %d %d",&s1,&s2,&s3,&s4,&s5);
sum=s1+s2+s3+s4+s5;
avg = sum/5;
printf("sum=%d average=%d \n",sum,avg);
if(s1<35 || s2<35 || s3<35 || s4<35 || s5<35)
{
printf(" failed");
}

118. if(avg>=80)
printf("\n\n Your Grade : A+");
else if(avg>=75)
printf("\n\n Your Grade : A");
else if(avg>=60)
printf("\n\n Your Grade : B");
else if(avg>=45)
printf("\n\n Your Grade : C");
else if(avg>=35)
printf("\n\n Your grade : D");
else
printf("\n\n You Are Fail");
return 0;
}
OUTPUT
Enter marks of 5 subjects each out of 100
89 78 65 57 46
sum=335average=67
YourGrade:B

119. Switch Statement
•Switchstatementisacontrolstatementthatallowsustochoose
onlyonechoiceamongthemanygivenchoices.
•Theexpressioninswitchevaluatesiscomparedtothevalues
presentindifferentcases.
•Itexecutesthatblockofcodewhichmatchesthecasevalue.
•Ifthereisnomatch,thendefaultblockisexecuted(ifpresent).

120. Switch Statement
switch(expression)
{
casevalue-1:
block-1;
break;
casevalue-2:
block-2;
break;
casevalue-3:
block-3;
break;
casevalue-4:
block-4;
break;
default:
default-block;
break;
}

121. Switch Statement Rules
1)Theswitchexpressionmustbeofanintegerorcharactertype.
2)Thecasevaluemustbeanintegerorcharacterconstant.
3)Thecasevaluecanbeusedonlyinsidetheswitchstatement.
4)Thebreakstatementinswitchcaseisnotmust.Itisoptional.If
thereisnobreakstatementfoundinthecase,allthecaseswillbe
executedpresentafterthematchedcase.

122. Switch Statement Example
#include<stdio.h>
intmain()
{
intch,n1,n2;
printf("1.Addition\n");
printf("2.subtraction\n");
printf("3.Multiplication\n");
printf("4.Division\n");
printf(“5.ModularDivision\n");
printf("enteryourchoice:");
scanf("%d",&ch);
printf("Entertwooperands:");
scanf("%d%d",&n1,&n2);
switch(ch)
{
case1:
printf(“sum=%d",n1+n2);
break;
case2:
printf(“sub=%d“,n1-n2);
break;
case 3:
printf(“mul= %d", n1*n2);
break;
case 4:
printf(“division = %d“,n1/n2);
break;
case 5: printf(“rem = %d“,n1%n2);
break;
default:
printf("Error! Select only from 1 to 4");
}
return 0;
}

123. OUTPUT
1. Addition
2. subtraction
3. Multiplication
4. Division
5.Modular Division
enter your choice : 2
Entertwooperands: 50 30
Sub = 20
OUTPUT
1. Addition
2. subtraction
3. Multiplication
4. Division
5.Modular Division
enter your choice : 6
Entertwooperands: 50 30
Error! Select only from 1 to 5

124. Switch Statement Example
#include<stdio.h>
intmain()
{
intn1,n2;
charch;
printf("1.Addition\n");
printf("2.subtraction\n");
printf("3.Multiplication\n");
printf("4.Division\n");
printf("enteryourchoice:");
scanf("%c",&ch);
printf("Entertwooperands:");
scanf("%d%d",&n1,&n2);
switch(ch)
{
case‘+’:
printf(“sum=%d",n1+n2);
break;
case‘-’:
printf(“sub=%d“,n1-n2);
break;
case ‘*’:
printf(“mul= %d", n1*n2);
break;
case ‘/’:
printf(“division = %d“,n1/n2);
break;
default:
printf("Error! Enter valid choice");
}
return 0;
}

125. OUTPUT
1. Addition
2. subtraction
3. Multiplication
4. Division
enter your choice : +
Entertwooperands: 50 30
Sum = 80
OUTPUT
1. Addition
2. subtraction
3. Multiplication
4. Division
enter your choice : &
Entertwooperands: 50 30
Error! Enter valid choice

126. Iterative Statements/ Loops
Aloopisusedtorepeatablockofcodeuntilthespecifiedcondition
ismet.Usingloopswedonotneedtowritethesamecodeagainand
again.
Cprogramminghasthreetypesofloops:
•whileloop
•do...whileloop
•forloop
Theseloopscontrolledeitheratentryleveloratexitlevelhenceloops
canbecontrolledtwoways:
1.Entry Controlled Loop
2.Exit Controlled Loop

127. Iterative Statements/ Loops
EntryControlledLoop
Loop,wheretestconditionischeckedbeforeenteringtheloopbody,
knownasEntryControlledLoop.Example:whileloop,forloop
ExitControlledLoop
Loop,wheretestconditionischeckedafterexecutingtheloopbody,
knownasExitControlledLoop.Example:dowhileloop

128. While Loop
•Thewhileloopisaddressedasentrycontrolledloop/pretestloop.
•Thewhileloopevaluatesthetestexpressioninsidetheparenthesis
().
•Ifthetestexpressionistrue,statementsinsidethebodyofwhile
loopareexecuted.Then,thetestexpressionisevaluatedagain.
•Theprocessgoesonuntilthetestexpressionisevaluatedtofalse.
•Ifthetestexpressionisfalse,theloopterminates(ends).

129. While Loop
Syntax:
while(testExpression)
{
//bodyoftheloop
}

130. While Loop-Example
//Printnumbersfrom1to5
#include<stdio.h>
intmain()
{
inti=1;
while(i<=5)
{
printf("%d\t",i);
i++;
}
return0;
}
//Printnumbersfrom1ton
#include<stdio.h>
intmain()
{
inti=1,n;
printf(“Entertherange:”);
Scanf(“%d”,&n);
while(i<=n)
{
printf("%d",i);
i++;
}
return0;
}
OUTPUT
12345
OUTPUT
Entertherange:10
12345678910

131. do-while Loop
•Thedo...whileloopisaddressedasexitcontrolledloop/posttest
loop
•Thebodyofdo...whileloopisexecutedatleastonce.Onlythen,
thetestexpressionisevaluated.
•Ifthetestexpressionistrue,thebodyoftheloopisexecutedagain
andthetestexpressionisevaluated.
•Thisprocessgoesonuntilthetestexpressionbecomesfalse.
•Ifthetestexpressionisfalse,theloopends.

132. do-while Loop
Syntax:
do
{
//bodyoftheloop
}
while(testExpression);

133. //Printnumbersfrom1to5
#include<stdio.h>
intmain()
{
inti=1;
do
{
printf("%d\t",i);
i++;
}while(i<=5);
return0;
}
//Printnumbersfrom1ton
#include<stdio.h>
intmain()
{
inti=1,n;
printf(“entertherange:”);
scanf(“%d”,&n);
do
{
printf("%d\t",i);
i++;
}while(i<=n);
return0;
}
Do-while Example
OUTPUT
12345
OUTPUT
Enter the range: 8
12345678

134. for Loop
Syntax:
for(initializationStatement;testExpression;updateStatement)
{
//bodyofloop
}

135. for Loop
•Theinitializationstatementisexecutedonlyonce.
•Then,thetestexpressionisevaluated.Ifthetestexpressionis
evaluatedtofalse,theforloopisterminated.
•However,ifthetestexpressionisevaluatedtotrue,statements
insidethebodyofforloopareexecuted,andtheupdateexpression
isupdated.
•Againthetestexpressionisevaluated.
•Thisprocessgoesonuntilthetestexpressionisfalse.Whenthe
testexpressionisfalse,theloopterminates.

136. #include<stdio.h>
intmain()
{
inti;
for(i=1;i<=5;i++)
{
printf("%d",i);
}
return0;
}
#include<stdio.h>
intmain()
{
inti,n;
printf(“Entertherange:”);
scanf(“%d”,&n);
for(i=1;i<=n;i++)
{
printf("%d",i);
}
return0;
}
//Printnumbersfrom1to5 //Printnumbersfrom1ton
for Loop-Example
OUTPUT
12345
OUTPUT
Enter the range: 12
1 2 3 4 5 6 7 8 9 10 11 12

137. Example Programs
//1.factorialofagivennumber
#include<stdio.h>
int main()
{
int i,fact=1,number;
printf("Enter a number: ");
scanf("%d",&num);
for(i=1;i<=num;i++)
{
fact=fact*i;
}
printf("Factorial of %d is: %d",num,fact);
return 0;
}
output
Enter a number: 5
Factorial of 5 is: 120

138. Example Programs
//2.sumofnnaturalnumbers
output
Enter a positive integer: 10
Sum = 55
#include <stdio.h>
int main()
{
int n, i, sum = 0;
printf("Enter a positive integer: ");
scanf("%d", &n);
for (i= 1; i<= n; ++i)
{
sum=sum+i;
}
printf("Sum = %d", sum);
return 0;
}

139. Example Programs
// 3. Multiplication Table Up to 10
output
Enter an integer: 9
9 * 1 = 9
9 * 2 = 18
9 * 3 = 27
9 * 4 = 36
9 * 5 = 45
9 * 6 = 54
9 * 7 = 63
9 * 8 = 72
9 * 9 = 81
9 * 10 = 90
#include <stdio.h>
int main()
{
int n, i;
printf("Enter an integer: ");
scanf("%d", &n);
for (i= 1; i<= 10; ++i)
{
printf("%d * %d = %d \n", n, i, n * i);
}
return 0;
}

140. Example Programs
// 4. sum of individual digits of a number
OUTPUT
Enter a number:654
Sum is=15
Enter a number:123
Sum is=6
#include<stdio.h>
int main()
{
int n,sum=0,rem;
printf("Enter a number:");
scanf("%d",&n);
while(n>0)
{
rem=n%10;
sum=sum+rem;
n=n/10;
}
printf("Sum is=%d",sum);
return 0;
}

141. Weoftencomeacrosssomesituationswherewewanttomakea
jumpfromonestatementtootherstatement,jumpoutofaloopor
tojumptonextiterationoftheloopinstantly,.
Thiscanbeaccomplishedbythestatementslike:
break
continue
goto
Jumps in loops:(unconditional statements)

142. Breakstatement
Thebreakstatementendstheloopimmediatelywhenitis
encountered.
Syntax:
break;

143. Breakstatement

144. Breakstatement-Example
# include <stdio.h>
int main()
{
int i;
for(i=1; i<= 10; i++)
{
if(i==6)
break;
printf("%d",i);
}
}
Output
1 2 3 4 5
# include <stdio.h>
int main()
{
int i=1;
while(i<= 10)
{
if(i==6)
break;
printf("%d",i);
i++;
}
}
Output
1 2 3 4 5

145. Breakstatement-Example
// Program to calculate the sum of a maximum of 10 numbers
// If a negative number is entered, the loop terminates
# include <stdio.h>
int main()
{
int i;
int number, sum = 0;
for(i=1; i<= 10; i++)
{
printf("Enter number %d: ",i);
scanf("%d",&num);
if(number < 0)
break;
sum = sum+ num;
}
printf("Sum = %d",sum);
}
output
Enter a number 1: 5
Enter a number 2: 6
Enter a number 3: 10
Enter a number 4: 45
Enter a number 5: 26
Enter a number 6: -56
Sum=92

146. continuestatement
Thecontinuestatementskipsthecurrentiterationoftheloopand
continueswiththenextiteration.
Syntax:
continue;
continue;

147. continuestatement

148. continuestatement-Example
# include <stdio.h>
int main()
{
int i;
for(i=1; i<= 10; i++)
{
if(i==6)
continue;
printf("%d",i);
}
}
Output
1 2 3 4 5 7 8 9 10
# include <stdio.h>
int main()
{
int i=0;
while(i<= 10)
{
i++;
if(i==6)
continue;
printf("%d",i);
}
}
Output
1 2 3 4 5 7 8 9 10

149. continuestatement-Example
// Program to calculate the sum of 10 positive numbers
// Negative numbers are skipped from the calculation
# include <stdio.h>
int main()
{
int i, num, sum = 0;
for(i=1; i<= 10; i++)
{
printf("Enter number%d: ",i);
scanf("%d",&num);
if(number < 0)
continue;
sum = sum+num;
}
printf("Sum = %d",sum);
}
output
Enter a number1 : 10
Enter a number2 : 20
Enter a number3 : 30
Enter a number4 : 40
Enter a number5 : 50
Enter a number6 : -5
Enter a number7 : 10
Enter a number8 : -8
Enter a number9 : 20
Enter a number10 : 30
Sum=210

150. gotostatement
ThegotostatementisknownasjumpstatementinC.
Thegotostatementallowsustotransfercontroloftheprogramtothe
specifiedlabel.
Syntax:
Thelabelisanidentifier.Whenthegotostatementisencountered,the
controloftheprogramjumpstolabel:andstartsexecutingthecode.

151. gotostatement-Example
#include <stdio.h>
int main()
{
int sum=0;
for(inti= 0; i<=10; i++)
{
sum = sum+i;
if(i==5)
{
goto addition;
}
}
addition:
printf(“sum =%d", sum);
return 0;
}
Output
sum=15

152. //program to find reverse of a given number
#include<stdio.h>
intmain()
{
intn,rev=0,rem;
printf("Enter a number:");
scanf("%d",&n);
while(n>0)
{
rem=n%10;
rev=rev*10+rem;
n=n/10;
}
printf(“Reverse of a given number is=%d",rev);
return 0;
}
OUTPUT
Enter a number:987
Reverse of a given number is= 789