array concepts explained with examples

1. Array
02/14/19PPSTheory
Er. Anupam Sharma
Assistant Professor
anupamcgctc@gmail.com

2. Contents
02/14/19PPSTheory
1 Array
2 Declaration and Initialization
3 Array Index
4 Accessing Array Elements and
Printing
5 Insertion
6 Insertion and Printing
7 Deleting / Removing of an element
8 Multi-dimensional Array
9 Printing 2D Array
10 Printing 3D Array

3. Textbook and Reference
Books
02/14/19PPSTheory
Textbook:
•Let Us C, by Yashavant Kanetkar, 13th Edition, Published by BPB Publications.
Reference books:
•Teach Yourself C, by Herbert Schildt, 4th Edition, Published by Osborne.
•Sams Teach Yourself C, by Bradley L. Jones & Peter Aitken, 6th Edition.
•The C Programming Language, by Brian W. Kernighan & Dennis M. Ritchie, 2nd
Edition, Published by Prentice Hall.

4. Array
02/14/19PPSTheory
An array is a collection of data storage locations, each storing the same
type of data and having the same name.
intnum ber[5]; floatmarks[10]; doublesalary[10]; charalphabet[5];
–Each storage location in an array is called an array
element.

5. Array (Cont’d)
02/14/19PPSTheory
–An array is a collection of variables of same data types.
–All elements of array are stored in the contiguous memory locations.
–The size of array must be a constant integral value.
–Individual elements in an array can be accessed by the name of the array and
an integer enclosed in square bracket called subscript/index variable like
number [10].
–The first element in an array is at index 0, whereas the last element is at index
[ArraySize - 1].

6. Array Declaration and Initialization
02/14/19PPSTheory
Array Declaration:
intnum ber[5]; floatmarks[5]; doublesalary[5];
Array Initialization:
marks[0] = 5;
marks[1] = 2;
marks[2] = 9;
marks[3] = 1;
marks[4] = 1;
Array Declaration and Initialization:
intnum ber[5] = {1 ,2 ,3 ,4 ,500};
floatscore[10] = {10 ,8 ,7 ,9 ,4.5 ,6 ,7 ,9 ,8.5 ,10};
doublesalary[5] = {10000.00 , 15000.00 , 20500.50 , 5050.50 , 3 0 0 0 0 .0 0 };
doublesalary[] = {10000.00 , 15000.00 , 20500.500 , 5050.50 , 3 0 0 0 0 .0 0 };
charalphabet[5] = { ’A ’ , ’B ’, ’C ’, ’D ’ , ’E ’};

7. Array Index
02/14/19PPSTheory
-Array index is the location of an element in an array
-You can access elements of an array by indices
-For example, Let’s get the following salary array elements using index
numbers -
1 doublesalary[5] = {10000.00 , 15000.00 , 20500.50 , 5050.50 , 3 0 0 0 0 .0 0 };
2 doublesalary1=salary[0];
3 doublesalary2=salary[1];
4 doublesalary3=salary[2];
5 doublesalary4=salary[3];
6 doublesalary5=salary[4];

8. Accessing elements using index and printing with loops
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 charalphabet[5]={ ’A ’, ’B ’, ’C ’,’D ’,’E ’};
4
5 /* Let ’s p rin t all a lp h a b ets one by one */
6 inti;
7 for(i=0;i<5;i++) {
8 printf( " c " ,alph abet[i]) ;
9 }
10 }
1 #include< stdio .h >
2 voidmain() {
3 doublesalary[] = {10000.00 , 15000.00 , 20500.50 ,
5050.50 , 3 0 0 0 0 .0 0 };
4
5 /* Let ’s p rin t all sa la ry one by one */
6 inti;
7 for(i=0;i<5;i++) {
8 printf( " S alary [ d ]: .2 lf n " ,i,salary[i]) ;
9 }
10 }

9. Accessing elements using index and printing with loops
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 charalphabet[5]={ ’A ’, ’B ’, ’C ’,’D ’,’E ’};
4
5 /* Let ’s p rin t all a lp h a b ets one by one */
6 inti;
7 for(i=0;i<5;i++) {
8 printf( " c " ,alph abet[i]) ;
9 }
10 }
1 #include< stdio .h >
2 voidmain() {
3 doublesalary[] = {10000.00 , 15000.00 , 20500.50 ,
5050.50 , 3 0 0 0 0 .0 0 };
4
5 /* Let ’s p rin t all sa la ry one by one */
6 inti;
7 for(i=0;i<5;i++) {
8 printf( " S alary [ d ]: .2 lf n " ,i,salary[i]) ;
9 }
10 }
Program Output:
A B C D E
Program Output:
S alary [0]: 10 00 0.0 0
S alary [1]: 15 00 0.0 0
S alary [2]: 20 50 0.5 0
S alary [3]: 5050.50
S alary [4]: 30 00 0.0 0

10. Insertion: Insert elements in an array
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 intsize= 5;
4 floatmarks[size];
5
6 /* In sertin g m arks into m a rks a rra y */
7 inti;
8 for(i= 0;i<=size;i++) {
9 printf( " Enter a mark : ");
10 scanf(" f" , &marks[i]) ;
11 }
12
13}

11. Insertion: Insert elements in an array
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 intsize= 5;
4 floatmarks[size];
5
6 /* In sertin g m arks into m a rks a rra y */
7 inti;
8 for(i= 0;i<=size;i++) {
9 printf( " Enter a mark : ");
10 scanf(" f" , &marks[i]) ;
11 }
12
13 }
Program Output:
Enter a mark : 50.5 Enter a mark :
40 Enter a mark : 30.5 Enter a
mark : 75.5 Enter a mark : 80 Enter
a mark : 90

12. Insertion and Printing
02/14/19PPSTheory
1 #include< stdio .h >
2 Void m ain () {
3 intsize= 5;
4 floatmarks[size];
5
6 /* In sertin g m arks into m a rks a rra y */
7 inti;
8 for(i= 0;i<=size;i++) {
9 printf( " Enter a marks : ");
10 scanf(" f" , &marks[i]) ;
11 }
12
13 /* Let ’s p rin t all m arks in the m a rks arra y */
14
15 printf( " n P rin tin g all marks : ");
16
17 intj;
18 for(j= 0;j<=size;j++) {
19 printf( " n . f " ,marks[j]) ;
20 }
21
22 }

13. Insertion and Printing
02/14/19PPSTheory
1 #include< stdio .h >
2 Void main() {
3 intsize= 5;
4 floatmarks[size];
5
6 /* In sertin g m arks into m a rks a rra y */
7 inti;
8 for(i= 0;i<=size;i++) {
9 printf( " Enter a marks : ");
10 scanf(" f" , &marks[i]) ;
11 }
12
13 /* Let ’s p rin t all m arks in the m a rks arra y */
14
15 printf( " n P rin tin g all marks : ");
16
17 intj;
18 for(j= 0;j<=size;j++) {
19 printf( " n .1 f " ,marks[j]) ;
20 }
21
22 }
Program Output:
Enter a marks : 80 Enter a
marks : 85.5 Enter a marks :
75 Enter a marks : 63.5
Enter a marks : 90 Enter a
marks : 11.0
P rin tin g all marks :
80.0
85.5
75.0
63.5
90.0

14. Deleting / Removing an element
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 int n_ array[5] = {11 , 12 , 13 , 14 , 15};
4
5 // let ’s p rin t all elem en ts in the n _ a rra y
6 printf( " Array before d eletion : n ");
7 inti;
8 for(i= 0;i< 5;i++) {
9 printf( " [ d ] d n " ,i, n_ array[i]) ;
10 }
11
12 printf( " let ’s delete elem ent at index 3 n ");
13 intindex;
14 for(index= 3 ;index< 5 - 1 ;index++) {
15 n _ array[index] = n _ array[index
+1];
16 }
17
18 printf( " Array after d eletion : n ");
19 for(i= 0;i< 5 - 1;i++) {
20 printf( " [ d ] d n " ,i, n _ array[i]) ;
21 }
22 }

15. Deleting / Removing an element
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 int n_array[5] = {11 , 12 , 13 , 14 , 15};
4
5 // let ’s p rin t all elem en ts in the n _ a rra y
6 printf( " Array before d eletion : n ");
7 inti;
8 for(i= 0;i< 5;i++) {
9 printf( " [ d ] d n " ,i, n_ array[i]) ;
10 }
11
12 printf( " let ’s delete elem ent at index 3 n ");
13 intindex;
14 for(index= 3 ;index< 5 - 1 ;index++) {
15 n _ array[index] =n _ array[index
+1];
16 }
17
18 printf( " Array after d eletion : n ");
19 for(i= 0;i< 5 - 1;i++) {
20 printf( " [ d ] d n " ,i,n_ array[i]) ;
21 }
22 }
Program Output:
Array before d eletion : [0] 11
[1] 12
[2] 13
[3] 14
[4] 15
let ’ s delete elem ent at index 3
Array after deletio n :
[0] 11
[1] 12
[2] 13
[3] 15

16. Multi-dimensional Array
02/14/19PPSTheory
Declaration:
inttable[2][3]; int th ree_ d _ array[3 ][3 ][3 ];
Declaration and Initialization:
inttable1[2][3] = {{1 ,2 ,3} ,{4 ,5 ,6}};
intgrid[][3] = {{1 ,2 ,3} ,{4 ,5 ,6}};
inttable2[2][3] = {1 ,2 ,3 ,4 ,5 ,6};
intth ree_ d _ array[3 ][3 ][3 ] = {
{{10 , 20 , 30} ,{40 , 50 , 60} ,{70 , 80 , 90}} ,
{{11 , 21 , 31} ,{41 , 51 , 61} ,{71 , 81 , 91}} ,
{{33 , 34 , 35} ,{36 , 37 , 38} ,{39 , 40 , 41}}
};

17. Printing 2D Array
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 introw= 3;
4 intcol= 4;
5 inttable[3][4] =
6 {
7 {1 , 2 , 3 , 4} ,
8 {10 , 11 , 12 , 13} ,
9 {20 , 21 , 22 , 23}
10 };
11 // p rin tin g 2 d a rra y
12 inti,j;
13 for(i= 0;i<row; ++i)
14 {
15 for(j= 0;j<col; ++j)
16 {
17 printf( " d " ,table[i][j]) ;
18 }
19 printf( " n ") ;
20 }
21
22 }

18. Printing 2D Array
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 introw= 3;
4 intcol= 4;
5 inttable[3][4] =
6 {
7 {1 , 2 , 3 , 4} ,
8 {10 , 11 , 12 , 13} ,
9 {20 , 21 , 22 , 23}
10 };
11 // p rin tin g 2 d a rra y
12 inti,j;
13 for(i= 0;i<row; ++i)
14 {
15 for(j= 0;j<col; ++j)
16 {
17 printf( " d " ,table[i][j]) ;
18 }
19 printf( " n ") ;
20 }
21
22 }
Program Output:
1 2 3 4
10 11 12 13
20 21 22 23

19. Printing 3D Array
// p rin tin g 3 d a rra y inti,j,k; for(i=0;i<x;i++)
{ for(j=0;j<y;j++) {
for(k=0;k<z;k++) {
printf( " d t " ,th ree_ d _ array[i][j][k]) ;
}
printf( " n ") ;
}
printf( " n ") ;
}
02/14/19PPSTheory
1#include< stdio .h >
2voidmain() {
3 intx= 3;inty= 3;intz= 3;
4 intth ree_ d _ array[3 ][3 ][3 ] = {
5 {{10 , 20 , 30} ,{40 , 50 , 60} ,{70 , 80 , 90}} ,
6 {{11 , 21 , 31} ,{41 , 51 , 61} ,{71 , 81 , 91}} ,
7 {{33 , 34 , 35} ,{36 , 37 , 38} ,{39 , 40 , 41}}
8 };
9
10
11
12
13
14
15
16
17
18
19
20
21
}

20. Printing 3D Array
// p rin tin g 3 d a rra y
inti,j,k; for(i=0;i<x;i++) { for(j=0;j<y;j++) {
for(k=0;k<z;k++) {
printf( " d t " ,th ree_ d _ array[i][j][k]) ;
}
printf( " n ") ;
}
printf( " n ") ;
}
02/14/19PPSTheory
1 #include< stdio .h >
2 voidmain() {
3 intx= 3;inty= 3;intz= 3;
4 intth ree_ d _ array[3 ][3 ][3 ] = {
5 {{10 , 20 , 30} ,{40 , 50 , 60} ,{70 , 80 , 90}} ,
6 {{11 , 21 , 31} ,{41 , 51 , 61} ,{71 , 81 , 91}} ,
7 {{33 , 34 , 35} ,{36 , 37 , 38} ,{39 , 40 , 41}}
8 };
9
10
11
12
13
14
15
16
17
18
19
20
21
}
Program Output:
10 20 30
40 50 60
70 80 90
11 21 31
41 51 61
71 81 91
33 34 35
36 37 38
39 40 41

21. 02/14/19PPSTheory
Thanks for your time and attention!
By: Anupam Sharma
sharmaanupam99@gmail.com