This document provides an overview of arrays in the C programming language. It defines arrays as collections of variables of the same data type stored in contiguous memory locations. The document discusses declaring, initializing, and accessing array elements using indices. It provides examples of inserting elements into arrays, deleting elements from arrays, and printing the contents of 1D and 2D arrays. The document is intended to teach the fundamentals of array programming in C.

1. CSI 123: Structured Programming Language
Array
Dr. Kamruddin Nur
Associate Professor & Chairman
kamruddin.nur@gmail.com
November, 2017
CSE
Department of
STAMFORD UNIVERSITY BANGLADESH
"Education for Tomorrow's World"

2. Contents
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
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 1 / 24

3. Textbook and Reference Books
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.
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 2 / 24

4. 1 Array
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 3 / 24

5. Array
– An array is a collection of data storage locations, each storing the same
type of data and having the same name.
int number [5];
float marks [10];
double salary [10];
char alphabet [5];
– Each storage location in an array is called an array element.
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 4 / 24

6. Array (Cont’d)
– 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].
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 5 / 24

7. 2 Declaration and Initialization
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 6 / 24

8. Array Declaration and Initialization
Array Declaration:
int number [5];
float marks [5];
double salary [5];
Array Initialization:
marks [0] = 5;
marks [1] = 2;
marks [2] = 9;
marks [3] = 1;
marks [4] = 1;
Array Declaration and Initialization:
int number [5] = {1 ,2 ,3 ,4 ,500};
float score [10] = {10 ,8 ,7 ,9 ,4.5 ,6 ,7 ,9 ,8.5 ,10};
double salary [5] = {10000.00 , 15000.00 , 20500.50 , 5050.50 , 30000.00};
double salary [] = {10000.00 , 15000.00 , 20500.500 , 5050.50 , 30000.00};
char alphabet [5] = {’A’, ’B’, ’C’, ’D’, ’E’};
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 7 / 24

9. 3 Array Index
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 8 / 24

10. Array Index
- 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 double salary [5] = {10000.00 , 15000.00 , 20500.50 , 5050.50 , 30000.00};
2 double salary1 = salary [0];
3 double salary2 = salary [1];
4 double salary3 = salary [2];
5 double salary4 = salary [3];
6 double salary5 = salary [4];
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 9 / 24

11. 4 Accessing Array Elements and Printing
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 10 / 24

12. Accessing elements using index and printing with loops
1 #include <stdio.h>
2 void main (){
3 char alphabet [5]={ ’A’,’B’,’C’,’D’,’E’};
4
5 /* Let ’s print all alphabets one by one */
6 int i;
7 for(i=0; i<5;i++){
8 printf("%c ", alphabet[i]);
9 }
10 }
1 #include <stdio.h>
2 void main (){
3 double salary [] = {10000.00 , 15000.00 , 20500.50 ,
5050.50 , 30000.00};
4
5 /* Let ’s print all salary one by one */
6 int i;
7 for(i=0; i<5;i++){
8 printf("Salary [%d]: %.2 lf n", i, salary[i]);
9 }
10 }
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 11 / 24

13. Accessing elements using index and printing with loops
1 #include <stdio.h>
2 void main (){
3 char alphabet [5]={ ’A’,’B’,’C’,’D’,’E’};
4
5 /* Let ’s print all alphabets one by one */
6 int i;
7 for(i=0; i<5;i++){
8 printf("%c ", alphabet[i]);
9 }
10 }
1 #include <stdio.h>
2 void main (){
3 double salary [] = {10000.00 , 15000.00 , 20500.50 ,
5050.50 , 30000.00};
4
5 /* Let ’s print all salary one by one */
6 int i;
7 for(i=0; i<5;i++){
8 printf("Salary [%d]: %.2 lf n", i, salary[i]);
9 }
10 }
Program Output:
A B C D E
Program Output:
Salary [0]: 10000.00
Salary [1]: 15000.00
Salary [2]: 20500.50
Salary [3]: 5050.50
Salary [4]: 30000.00
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 11 / 24

14. 5 Insertion
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 12 / 24

15. Insertion: Insert elements in an array
1 #include <stdio.h>
2 void main (){
3 int size = 5;
4 float marks[size ];
5
6 /* Inserting marks into marks array */
7 int i;
8 for(i = 0; i <= size; i++){
9 printf("Enter a mark: ");
10 scanf("%f", &marks[i]);
11 }
12
13 }
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 13 / 24

16. Insertion: Insert elements in an array
1 #include <stdio.h>
2 void main (){
3 int size = 5;
4 float marks[size ];
5
6 /* Inserting marks into marks array */
7 int i;
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
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 13 / 24

17. 6 Insertion and Printing
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 14 / 24

18. Insertion and Printing
1 #include <stdio.h>
2 void main (){
3 int size = 5;
4 float marks[size ];
5
6 /* Inserting marks into marks array */
7 int i;
8 for(i = 0; i <= size; i++){
9 printf("Enter a marks: ");
10 scanf("%f", &marks[i]);
11 }
12
13 /* Let ’s print all marks in the marks array */
14
15 printf("nPrinting all marks:");
16
17 int j;
18 for(j = 0; j <= size; j++){
19 printf("n%.1f ", marks[j]);
20 }
21
22 }
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 15 / 24

19. Insertion and Printing
1 #include <stdio.h>
2 void main (){
3 int size = 5;
4 float marks[size ];
5
6 /* Inserting marks into marks array */
7 int i;
8 for(i = 0; i <= size; i++){
9 printf("Enter a marks: ");
10 scanf("%f", &marks[i]);
11 }
12
13 /* Let ’s print all marks in the marks array */
14
15 printf("nPrinting all marks:");
16
17 int j;
18 for(j = 0; j <= size; j++){
19 printf("n%.1f ", 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
Printing all marks:
80.0
85.5
75.0
63.5
90.0
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 15 / 24

20. 7 Deleting / Removing of an element
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 16 / 24

21. Deleting / Removing an element
1 #include <stdio.h>
2 void main (){
3 int number_array [5] = {11, 12, 13, 14, 15};
4
5 // let ’s print all elements in the number_array
6 printf("Array before deletion: n");
7 int i;
8 for (i = 0; i < 5; i++) {
9 printf("[%d] %d n", i, number_array [i]);
10 }
11
12 printf("let’s delete element at index 3 n");
13 int index;
14 for (index = 3 ; index < 5 - 1 ; index ++){
15 number_array [index] = number_array [index
+1];
16 }
17
18 printf("Array after deletion: n");
19 for (i = 0; i < 5 - 1; i++) {
20 printf("[%d] %d n", i, number_array [i]);
21 }
22 }
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 17 / 24

22. Deleting / Removing an element
1 #include <stdio.h>
2 void main (){
3 int number_array [5] = {11, 12, 13, 14, 15};
4
5 // let ’s print all elements in the number_array
6 printf("Array before deletion: n");
7 int i;
8 for (i = 0; i < 5; i++) {
9 printf("[%d] %d n", i, number_array [i]);
10 }
11
12 printf("let’s delete element at index 3 n");
13 int index;
14 for (index = 3 ; index < 5 - 1 ; index ++){
15 number_array [index] = number_array [index
+1];
16 }
17
18 printf("Array after deletion: n");
19 for (i = 0; i < 5 - 1; i++) {
20 printf("[%d] %d n", i, number_array [i]);
21 }
22 }
Program Output:
Array before deletion:
[0] 11
[1] 12
[2] 13
[3] 14
[4] 15
let ’s delete element at
index 3
Array after deletion:
[0] 11
[1] 12
[2] 13
[3] 15
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 17 / 24

23. 8 Multi-dimensional Array
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 18 / 24

24. Multi-dimensional Array
Declaration:
int table [2][3];
int three_d_array [3][3][3];
Declaration and Initialization:
int table1 [2][3] = {{1 ,2 ,3} ,{4 ,5 ,6}};
int grid [][3] = {{1 ,2 ,3} ,{4 ,5 ,6}};
int table2 [2][3] = {1,2,3,4,5,6};
int three_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}}
};
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 19 / 24

25. 9 Printing 2D Array
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 20 / 24

26. Printing 2D Array
1 #include <stdio.h>
2 void main (){
3 int row = 3;
4 int col = 4;
5 int table [3][4] =
6 {
7 {1, 2, 3, 4},
8 {10, 11, 12, 13},
9 {20, 21, 22, 23}
10 };
11 // printing 2d array
12 int i,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 }
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 21 / 24

27. Printing 2D Array
1 #include <stdio.h>
2 void main (){
3 int row = 3;
4 int col = 4;
5 int table [3][4] =
6 {
7 {1, 2, 3, 4},
8 {10, 11, 12, 13},
9 {20, 21, 22, 23}
10 };
11 // printing 2d array
12 int i,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
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 21 / 24

28. 10 Printing 3D Array
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 22 / 24

29. Printing 3D Array
1 #include <stdio.h>
2 void main (){
3 int x = 3; int y = 3; int z = 3;
4 int three_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 // printing 3d array
11 int i,j,k;
12 for(i=0;i<x;i++){
13 for(j=0;j<y;j++){
14 for(k=0;k<z;k++){
15 printf("%dt",three_d_array [i][j][k]);
16 }
17 printf("n");
18 }
19 printf("n");
20 }
21 }
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 23 / 24

30. Printing 3D Array
1 #include <stdio.h>
2 void main (){
3 int x = 3; int y = 3; int z = 3;
4 int three_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 // printing 3d array
11 int i,j,k;
12 for(i=0;i<x;i++){
13 for(j=0;j<y;j++){
14 for(k=0;k<z;k++){
15 printf("%dt",three_d_array [i][j][k]);
16 }
17 printf("n");
18 }
19 printf("n");
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
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 23 / 24

31. Thanks
Thanks for your time and attention!
kamruddin.nur@gmail.com
sites.google.com/view/kamruddinnur
CSE
Department of
STAMFORD UNIVERSITY BANGLADESH
"Education for Tomorrow's World"
CSI 123: Structured Prog. Language Dr. Kamruddin Nur November, 2017 24 / 24