This document provides an overview of structures in C programming. It defines structures as named collections of data items of different data types that are accessed by name. It discusses defining and declaring structures, initializing and accessing members, nested structures, arrays of structures, unions, and the typedef keyword as it relates to structures. The document aims to explain these fundamental concepts of structures in C to help readers better understand how to use structures in their own programs.

1. Established as per the Section 2(f) of the UGC Act, 1956
Approved by AICTE, COA and BCI, New Delhi
Structures in C Programming
N i m r i t a K o u l
n i m r i t a k o u l @ r e v a . e d u . i n

2. OUTLINE
• Quick Recap
• Structure Type
• Definition & Declaration
• Member Initialization and Access
• Nested Structures
• Arrays of Structures
• Union
• typedef
• What Next?

3. RECAP - C ROCKS. EVEN TODAY!!
Image Source: https://www.edureka.co/blog/c-programming-tutorial/

4. PROGRAM
PROCEDURE DATA
ALGORITHM + DATA STRUCTURE = PROGRAM

5. TYPICAL CONSTITUENTS OF A C PROGRAM

6. THE PROCESS OF WRITING A C PROGRAM
Source: https://www3.ntu.edu.sg/home/ehchua/programming/cpp/c0_Introduction.html

7. CONSTRUCTS OF C LANGUAGE

8. C DATA TYPES
Image Source: https://www.edureka.co/blog/c-programming-tutorial/
C DATA
TYPES

9. C DATATYPES
Enumerated
types
void
Derived Types –
• Pointers
• Arrays
• Functions
• Structures
• Unions
• Basic Types – Integer types, floating
point types
• Integer - Char, unsigned char, int,
unsigned int, short, unsigned short, long,
unsigned long
• Floating types -Float, double, long
double

10. WHY DO WE NEED STRUCTURE DATA TYPE?

11. CARS IN MY GARAGE AND THEIR SPECIFICATIONS
Credits: https://www.youtube.com/watch?v=zmRxC7gYw-g

12. ALL DATA ABOUTCAR-1 I NEED TO STORE -

13. ANOTHER CAR

14. CREATING TOO MANY VARIABLES?

15. CONSIDERING ARRAY?

16. SO WHAT TO DO?
WHAT IF WE CAN DEFINE OUR OWN DATA
TYPE THAT CAN ACCOMMODATE INDIVIDUAL
PIECES OF INFORMATION OF DIFFERENT DATA
TYPES!!!

17. STRUCTURE IS THE WAY TO GO.
STRUCTURE IS ONE
STOP SOLUTION.

18. DEFINITION
1. A structure is a namedcollectionof dataitems of different datatypes.
2. Eachelement or member orfield withinthe struct are accessed by nameinstead of aninteger index.
3. Structs are very powerful for bundling together data items that collectively describe a thing, or are in some
other wayrelated to eachother.

19. STRUCTURES
Name of Structure
Member 1 Member 2
Member 3 Member 4
Member 5 Member 5 Member 5 Member 5
STRUCTURE

20. EXAMPLES
1. Studentrecord: student id, name, major, gender, start year, …
2. Bank account: account number, name, currency, balance, …
3. Address book: name, address, telephone number, …

21. C NOTATION
1. A structure inClanguageis defined withthekeyword‘struct’
2. Individualcomponents ofa struct type are called members(or fields).
3. Members canbe ofdifferent types (simple,array or struct).
4. A struct is namedas a wholewhileindividualmembers arenamedusing field identifiers.
5. Complexdata structures canbeformed bydefiningarrays of structs.

22. GENERAL SYNTAX FOR DECLARING A STRUCTURE

23. DEFINITION
1. Definition of a structure:
struct <struct-type>{
<type> <identifier_list>;
<type> <identifier_list>;
...
} ;
Example:
struct Date {
int day;
int month;
int year;
} ;
Each identifier
defines a member
of the structure.
The “Date” structure
has 3 members,
day, month & year.

24. struct examples
• Example:
struct StudentInfo{
int Id;
int age;
char Gender;
double CGA;
};
• Example:
struct StudentGrade{
char Name[15];
char Course[9];
int Lab[5];
int Homework[3];
int Exam[2];
};
The “StudentGrade”
structure has 5
members of
different array types.
The “StudentInfo”
structure has 4 members
of different types.

25. struct basics
• Declaration of a variable of struct type:
<struct-type> <identifier_list>;
StudentRecord Student1, Student2;
Student1 Student2
Name
Id Gender
Dept
Name
Id Gender
Dept
struct StudentRecord{
char Name[15];
int Id;
char Dept[5];
char Gender;
};

26. struct examples
• Example:
struct BankAccount{
char Name[15];
int AcountNo[10];
double balance;
Date Birthday;
};
The “BankAcount”
structure has simple,
array and structure
types as members.

27. 27
Nimrita
12345 F
CSE
DOT OPERATOR FOR ACCESS
• The members of a struct type variable are accessed
with the dot (.) operator:
<struct-variable>.<member_name>;
• Example:
strcpy(Student1.Name, “Nimrita");
Student1.Id = 12345;
strcpy(Student1.Dept, “CSE");
Student1.gender = ‘F';
printf("The student is “);
switch (Student1.gender){
case 'F': printf("Ms. “); break;
case 'M': printf(“Mr. “); break;
}
printf(Student1.Name);
Student1
Name
Id Gender
Dept

28. OH YES!! LETS REVISIT MY GARAGE!

29. ACCESSING MEMBERS OF MY CARS

30. MEMORY ALLOCATED TO A STRUCTURE

31. STRUCUTRE PADDING

32. MEMORY REQUIRED BY A STRUCTURE
a b c c c c Memory Arrangement
2 bytes padding

33. CHANGE IN ORDER OF MEMBERS CHANGES THE MEMORY REQUIRED BY
STRUCTURE VARIABLE
a b b b b c

34. NESTED STRUCTURE IN C: STRUCT INSIDE ANOTHER STRUCT
You can use a structure inside another structure.
Inner structure is called a Nested Structure.

35. ANY LEVEL OF NESTING IS POSSIBLE

36. Nested structures
• We can nest structures inside structures.
• struct line{
point p1, p2;
};
line L;
(L.p1.x, L.p1.y)
(L.p2.x, L.p2.y)
line
p1 p2
x y x y

37. Nested structures
• Examples:
struct point{
double x, y;
};
point P;
struct line{
point p1, p2;
};
line L;
struct triangle{
point p1, p2, p3;
};
triangle T;
(P.x, P.y)
(L.p1.x, L.p1.y)
(L.p2.x, L.p2.y)
(T.p2.x, T.p2.y)
(T.p1.x, T.p1.y)
(T.p3.x, T.p3.y)

38. Nested structures
point P;
line L;
triangle T;
P.x = 4;
P.y = 11;
(4, 11)
(2, 7)
(10, 9)
(6, 5)
(2, 0)
(8, 3)
L.p1.x = 2;
L.p1.y = 7;
L.p2.x = 10;
L.p2.y = 9;
T.p1.x = 2;
T.p1.y = 0;
T.p2.x = 6;
T.p2.y = 5;
T.p3.x = 8;
T.p3.y = 3;

39. Nirmtia
12345 F
CSE
struct-to-struct assignment
• The values contained in one struct type variable can
be assigned to another variable of the same struct
type.
• Example:
strcpy(Student1.Name, Nimrita");
Student1.Id = 12345;
strcpy(Student1.Dept, "CSE");
Student1.gender = ‘F';
Student2 = Student1;
Student1
Nimrita
12345 F
CSEStudent2

40. PASSING STRUCTURES AS PARAMETERS TO FUNCTIONS
• Structs can be passed to and from
functions just like any basic data
types.
• Individual structs are always passed
by value, even if they contain arrays.
• The struct definition must be
known to both the calling and
called functions, which means it
is must be defined globally.
• However the actual
struct variables should still be
declared locally, just like any
other variables.• Arrays of structs are passed by
pointer / address.

41. Structure Definition
Main Function
Function Definition

42. ARRAY OF STRUCTURES
Array of structures is a collection of
structure variables of same type.

43. ARRAYS OF STRUCTURES
• An ordinary array: One type of data
• An array of structs: Multiple types of data in each array
element.
0 1 2 … 98 99
0 1 2 … 98 99

45. ARRAYS OF STRUCTURES
• Example:
StudentRecord Class[100];
strcpy(Class[98].Name, “Nimrita");
Class[98].Id = 12345;
strcpy(Class[98].Dept, "CSE");
Class[98].gender = ‘F';
Class[0] = Class[98];
. . .
0 1 2 … 98 99
Nimrita
12345 F
CSE

46. TWO WAYS TO DECLARE AN ARRAY OF STRUCTURES

47. EXAMPLE OF ARRAY OF STRUCTURES

48. ARRAYS INSIDE STRUCTURES
• We can use arrays inside structures.
• Example:
struct square{
point vertex[4];
};
square Sq;
(4, 3) (10, 3)
(4, 1) (10, 1)
x y x y x y x y

49. ARRAY VS STRUCTURE

50. UNION
• A union like a structure is a PROGRAMMER DEFINED
data type.
• It can hold heterogeneous data types in same memory
location.
• You can define a union with many members, but only
one member can contain a value at any given time.

51. STR VS UNION MEMORYREQUIREMENT

53. ACCESSING MEMBERS OF UNION
To access any member of a union,
weuse the memberaccessoperator (.).

56. TYPEDEF
1. Typedef is a keyword used to define your own identifiers that can be used in place of other type specifiers
such as int, float,anddouble.
2. Typedef creates synonyms for the datatypes or combinationsofdata types they represent.

57. USE OF TYPEDEF IN STRUCTURE
• A typedef cansimplify the declarationfor a structure.
• Itmakes the code short andimproves readability.
• Itis likeanaliasof struct.

58. TYPEDEF SYNTAX

59. TYPEDEF

60. LIMITATIONS OF STRUCTURES
•No Data Hiding
•No Functions inside Structure
•No Static Members
•No Access Modifiers
•No Constructors

61. What can you do with knowledge of
C programming?

62. APPLICATIONS OF C PROGRAMMING
Source: www.daataflair.com

63. WHAT CAN YOU EASILY BUILD WITH C?
1.OperatingSystems
2.LanguageCompilers
3.Assemblers
4.TextEditors
5.PrintSpoolers
6.NetworkDrivers
7.ModernPrograms
8.DataBases
9.LanguageInterpreters
10.Utilities
Interpreted languages
likePython,Ruby,and PHP have their
primary implementations written in
C.

64. OPPORTUNITIES AT SCHOOL OF CIT, REVA UNIVERSITY
• B.Tech(CSE)
• B.Tech(CS & IT)
• B.Tech(AI & ML)
• B.Tech(ISE)
• M.Tech( CSE)
• M.Tech (DECC)
• Hackathons
• WorkshopsandSkill
• Development Programs
• International Internships and
Project Expos
Latest Industry Oriented Curriculum -
• ProgrammingTechnologies -Cprogramming,Python
Programming,
Java Programming,R Programming etc.
• Web Technologies – PHP,Perl, Java Script, NodeJS,
Angular JSetc.
• Machine Learning, Deep Learning,
Blockchain,CloudComputing,Mobile
Application Development, DevOps,
Wireless and Sensor Networks
And manymore…

66. REFERENCES
• https://www.youtube.com/watch?v=zmRxC7gYw-g
• https://www.tutorialspoint.com/cprogramming/c_unions.htm#:~:text=A%20union%20is%20a%20special,memory%20location%20fo
r%20multiple%2Dpurpose.
• https://www.programiz.com/c-programming/examples/information-structure-array
• https://fresh2refresh.com/c-programming/c-structures/
• https://study.com/academy/lesson/practical-application-for-c-programming-structures-unions.html
• http://www.c4learn.com/c-programming/c-structure-applications/

67. PROGRAMS

68. THANK YOU