Array and its types and it's implemented programming Final.pdf

What is Array and it's types

1. Arrays:
Anarrayisacollectionofdatathatholds
fixednumberofvaluesofsametype.
Thesizeandtypeofarrayscannotbe
changedafteritsdeclaration.
ForExample:Ifyouwanttostoremarks
of100studentsyoucancreateanarrayforit.
floatmarks[100];

2. Someexampleswheretheconceptofan
arraycanbeused:
•Listoftemperaturesrecordedeveryhourinaday,ora
month
orayear.
•Listofemployeesinanorganization.
•Listofproductsandtheircostsoldbyastore.
•Testscoresofaclassofstudents.
•Listofcustomersandtheirtelephonenumbers.
•Tableofdailyrainfalldata.

3. HowtodeclareanarrayinC?
Syntax:
data_typearray_name[array_size];
Forexample:
floatmark[5];
Herewedeclaredanarray,mark,of
floating-pointtypeandsize5.Thatitholds5
floating-pointvalues.

4. ElementsofanarrayandHowtoaccessthem?
Youcanaccesselementsofanarraybyindices.
Supposeyoudeclaredanarraymarkasabove.Thefirst
elementismark[0],secondelementismark[1]andsoon.
FewKeypoints:
•Arrayshave0asthefirstindexnot1.Inthisexample,
mark[0].
•Ifthesizeofanarrayisn,toaccessthelastelement,(n-1)
indexisused.Inthisexample,mark[4].
•Supposethestartingaddressofmark[0]is2120d.Then,the
nextaddress,mark[1],willbe2124d,addressofmark[2]will
be2128dandsoon.Itsbecausethesizeofafloatis4bytes.

5. HowtoInitializeanarray?
Itspossibletoinitializeanarrayduringdeclaration.
Forexample:
intmark[5]={9,4,6,3,5};
Anothermethodofinitializearrayduringdeclaration
intmark[]={9,4,6,3,5};
Here,
mark[0]isequalto9
mark[1]isequalto4
mark[2]isequalto6
mark[3]isequalto3
mark[4]isequalto5

6. Importantthingtorememberwhenworkingwith
Carrays:
Supposeyoudeclaredanarrayof10elements.Letssay,
inttestArray[10];
YoucanusethearraymembersfromtestArray[0]to
testArray[9].
Ifyoutrytoaccessarrayelementsoutsideofitsbound,lets
saytestArray[12],thecompilermaynotshowanyerror.
However,thismaycauseunexpectedoutput(undefined
behavior).

7. Arrays are of three types:
1.One-dimensional arrays.
2.Two-dimensional arrays.
3.Multidimensional arrays.

8. One-dimensionalArray:
Alistofitemcanbegivenonevariablenameusing
onlyonesubscriptandsuchavariableiscalledasinglesubscripted
variableoraonedimensionalarray.
TheSyntaxforanarraydeclarationis:
typevariable-name[size];
Example:
floatheight[50];
intgroupt[10];
charname[10];

9. Thetypespecifiesthetypeoftheelementthatwillbe
containedinthearray,suchasint,float,orcharandthesize
indicatesthemaximumnumberofelementsthatcanbestored
insidethearray.
Nowaswedeclareaarray
intnumber[5];
Thenthecomputerreservesfivestoragelocationsas
thesizeothearrayis5asshowbelow.
ReservedSpace StoringvaluesafterInitialization
number[0] number[0]
number[1] number[1]
number[2] number[2]
number[3] number[3]
number[4] number[4]
35
20
40
57
19

10. Initializationofonedimensionalarray:
Afteranarrayisdeclared,itselementsmustbe
initialized.InCprogramminganarraycanbeinitializedat
eitherofthefollowingstages:
Atcompiletime
Atruntime

11. CompileTimeInitialization:
Thegeneralformofinitializationofarrayis:
typearray-name[size]={listofvalues};
Thevaluesinthelistareseparatedbycommas.
Forexample:
intnumber[3]={0,5,4};
willdeclarethevariable‘number’asanarrayof
size3andwillassignthevaluestoeachelements.
Ifthenumberofvaluesinthelistislessthanthe
numberofelements,thenonlythatmanyelementswillbe
initialized.
Theremainingelementswillbesettozero
automatically.
Remember,ifwehavemoreinitializersthanthe
declaredsize,thecompilerwillproduceanerror.

12. Runtimeinitialization:
Anarraycanalsobeexplicitlyinitializedatruntime.
Forexampleconsiderthefollowingsegmentofacprogram.
for(i=0;i<10;i++)
{
scanf(“%d”,&x[i]);
}
Intheruntimeinitializationofthearrayslooping
statementsarealmostcompulsory.
Loopingstatementsareusedtoinitializethevaluesofthe
arraysonebyoneusingassignmentoperatororthroughthe
keyboardbytheuser.

13. OnedimensionalArrayProgram:
#include<stdio.h>
voidmain()
{
intarray[5];
printf(“Enter5numberstostoretheminarray\n”);
for(i=0;i<5;i++)
{
Scanf(“%d”,&array[i]);
}
printf(“Elementinthearrayare:\n”);
For(i=0;i<5;i++)
{
printf(“Elementstoredata[%d]=%d\n”,i,array[i]);
}
getch();
}

14. Input:
Enter 5 elements in the array: 23 45 32 25 45
Output:
Element in the array are:
Element stored at a[0]:23
Element stored at a[0]:45
Element stored at a[0]:32
Element stored at a[0]:25
Element stored at a[0]:45

15. Two-dimensionalArrays:
Thesimplestformofmultidimensionalarrayis
thetwo-dimensionalarray.Atwo-dimensionalarrayis,in
essence,alistofone-dimensionalarrays.
Todeclareatwo-dimensionalintegerarrayof
size[x][y],youwouldwritesomethingasfollows:
typearrayName[x][y];
WheretypecanbeanyvalidCdatatypeand
arrayNamewillbeavalidCidentifier.

16. Atwo-dimensionalarraycanbeconsideredas
atablewhichwillhavexnumberorowsandynumbero
columns.
Atwo-dimensionalarraya,whichcontains
threerowsandfourcolumnscanbeshownasfollows.
Column0Column1Column2Column3
Row0
Row1
Row2
a[0][0] a[0][1]
a[0][2] a[0][3]
a[0][2] a[0][2] a[0][2] a[0][2]
a[0][2] a[0][2] a[0][2] a[0][2]

17. Thus,everyelementinthearrayaisidentified
byanelementnameoftheforma[i][j].
where‘a’isthenameofthearray,and‘i’and‘j’
arethesubscriptsthatuniquelyidentifyeachelementin‘a’.
InitializingTwo-DimensionalArrays:
Multidimensionalarraysmaybeinitializedby
specifyingbracketedvaluesforeachrow.

18. Followingisanarraywith3rowsandeachrow
has4columns.
inta[3][4]={
{0,1,2,3},
{4,5,6,7},
{8,9,10,11}
};
Thenestedbraces,whichindicatetheintended
row,areoptional.Thefollowinginitializationisequivalent
tothepreviousexample
inta[3][4]={0,1,2,3,4,5,6,7,8,9,10,11};

19. AccessingTwo-DimensionalArrayElements:
Anelementinatwo-dimensionalarrayis
accessedbyusingthesubscripts.i.e.,rowindexand
columnindexofthearray.
ForExample:
intval=a[2][3];
Theabovestatementwilltakethe4
th
element
fromthe3
rd
rowofthearray.

20. Two-Dimensional Arrays program:
#include<stdio.h>
int main()
{
int a[5][2]={{0,0},{1,2},{2,4},{3,6},{4,8}};
int i,j;
for(i=0;i<5;i++)
{
for(j=0;j<2;j++)
{
printf(“a[%d][%d] = %d\n”,i,j,a[i][j]);
}
}
return 0;
}

21. Output:
a[0][0]: 0
a[0][1]: 0
a[1][0]: 1
a[1][1]: 2
a[2][0]: 2
a[2][1]: 4
a[3][0]: 3
a[3][1]: 6
a[4][0]: 4
a[4][1]: 8

22. Multi-DimensionalArrays:
C programming languagesupports
multidimensionalArrays.
•Multidimensionalarrayshavemorethanone
subscriptvariables.
•Multidimensionalarrayisalsocalledasmatrix.
•Multidimensionalarraysarearrayoarrays.

23. DeclarationofMultidimensionalArray
Amultidimensionalarrayisdeclaredusingthe
followingsyntax
Syntax:
data_typearray_name[d1][d2][d3][d4]....[dn];
AbovestatementwilldeclareanarrayonN
dimensionsofnamearray_name,whereeachelementof
arrayisoftypedata_type.
Themaximumnumberofelementsthatcanbe
storedinamultidimensionalarrayarray_nameissize1X
size2Xsize3....sizeN.
Forexample:
charcube[50][60][30];

24. Multidimensional Array program:
#include<stdio.h>
int main()
{
int r,c,a[50][50],b[50][50],sum[50][50],i,j;
printf("\t\n Multi-dimensional array");
printf("\n Enter the row matrix:");
scanf("%d",&r);
printf("\n Enter the col matrix:");
scanf("%d",&c);
printf("\n Element of A matrix");
for(i=0;i<r;++i)
for(j=0;j<c;++j)

25. {
printf("\n a[%d][%d]:",i+1,j+1);
scanf("%d",&a[i][j]);
}
printf("\n Element of B matrix");
for(i=0;i<r;++i)
for(j=0;j<c;++j)
{
printf("\n b[%d][%d]:",i+1,j+1);
scanf("%d",&b[i][j]);
}
printf("\n Addition of matrix");
for(i=0;i<r; i++)

26. {
for(j=0;j<c;j++)
sum[i][j]=a[i][j]+b[i][j];
}
for(i=0;i<r;i++)
{
printf("\n");
for(j=0;j<c;j++)
{
printf("\t%d",sum[i][j]);
}
printf("\n\t");
}

27. if(j==c-1)
{
printf("\n");
}
return 0;
}

28. Output
Multidimensional array
Enter the row matrix:2
Enter the col matrix:2
Element of A matrix
a[1][1]:1
a[1][2]:4
a[2][1]:6
a[2][2]:3

29. Element of B matrix
b[1][1]:1
b[1][2]:7
b[2][1]:3
b[2][2]:9
Addition of a matrix is
2 11
9 12