Structures in C Programming In C, a structure is a user-defined data type that allows you to group different types of variables under a single name. It is very useful when you want to represent a real-world entity (like a student, employee, or gene record) with multiple attributes. ### **Structures in C Programming** In **C**, a **structure** is a user-defined data type that allows you to group **different types of variables** under a single name. It is very useful when you want to represent a real-world entity (like a student, employee, or gene record) with multiple attributes. --- ## **1. Definition of Structure** A structure is defined using the `struct` keyword. ```c struct Student { int roll_no; char name[50]; float marks; }; ``` Here, `Student` is a structure that contains **int, char array, and float**. --- ## **2. Declaring Structure Variables** ```c struct Student s1, s2; ``` OR during definition: ```c struct Student { int roll_no; char name[50]; float marks; } s1, s2; ``` --- ## **3. Accessing Structure Members** Use the **dot (.) operator**. ```c s1.roll_no = 101; s1.marks = 85.5; strcpy(s1.name, "Amina"); ``` --- ## **4. Structure Initialization** ```c struct Student s1 = {101, "Amina", 85.5}; ``` --- ## **5. Array of Structures** Used to store multiple records. ```c struct Student s[3]; for(int i = 0; i < 3; i++) { scanf("%d %s %f", &s[i].roll_no, s[i].name, &s[i].marks); } ``` --- ## **6. Structures and Functions** ### Passing structure to a function ```c void display(struct Student s) { printf("%d %s %.2f", s.roll_no, s.name, s.marks); } ``` ### Passing structure by reference ```c void display(struct Student *s) { printf("%d %s %.2f", s->roll_no, s->name, s->marks); } ``` --- ## **7. Structure Pointer** ```c struct Student s1; struct Student *ptr = &s1; ptr->roll_no = 102; ``` (`->` is called the **arrow operator**) --- ## **8. Nested Structures** Structure inside another structure. ```c struct Address { char city[20]; int pincode; }; struct Student { int roll_no; struct Address addr; }; ``` --- ## **9. typedef with Structure** Used to avoid writing `struct` repeatedly. ```c typedef struct { int id; float salary; } Employee; Employee e1; ``` --- ## **10. Advantages of Structures** * Groups related data * Improves program readability * Useful for large programs and data management * Widely used in **file handling**, **databases**, and **bioinformatics data structures** --- ## **11. Structure vs Union (Short Note)** | Structure | Union | | -------------------------------- | ------------------------------ | | Each member has its own memory | Members share same memory | | Larger size | Sm- ### **Conclusion – Structures in C Programming** Structures in C provide an efficient way to store and manage related data of different data types under a singl

1. STRUCTURES
IN C PROGRAMMING
By
Fathima C.Asees

2. Introduction Structure
Declaring Structure Variable
Structure Initialization
Accessing member of Structure
Copying & Comparing Structure Variable
Array of Structures
Conclusion
Reference
CONTENTS

3. INTRODUCTION
Structure are collection of different datatype grouped
together under a single variable name for convienient
handling. 'struct' is a keyword, struct type is a name
which identifies the structure.
syntax: struct <structure name >
{
datatype member1;
datatype member2;
};
Example:
struct employee
int id;
char name[10];
Float salary;
};

4. DECLARING STRUCTURE VARIABLES
• Structure variable declaration is similar to the declaration of variables of any other data types.
• Structure variables can be declared in following two ways
1.Declaring Structure variable separately
Struct employee,
{
int id;
char name [10];
float salary;
};
void main()
{
struct employee e1, e2;

5. 2.Declarimg structure variable with in structure definintion
Struct employee
{
int id;
char name (10);
float salary;
}e1,e2;
notes:
If no: of variable are not fixed 1st way, it provide you the flexibility to declare the
structure variable many times
If no: of variables are fixed use 2nd way. It save your code to declare a variable in
main () function.

6. •Like any other data type, structure variable can also be initialized at compile time.
Syntax: struct structure_name variable={value 1,value 2,value 3,......value n}
Eg: struct employee
{
int id;
char name [10];
float salary;
}
void main()
{
struct employee e1= {01, "Joy", 1000 };
struct employee e={02, "Ram",2000};
STRUCTURE INITIALIZATION

7. ACCESSING MEMBER OF STRUCTURE
•By using dot (.) operator or member operator
Syntax: structure variable.member
Eg: struct employee
{
int id;
char name [10];
float salary;
};
void main();
{
struct employee e1 = {01, "Joy", 1000 };
printf("%d",e1.id);

8. COPYING AND COMPARING STRUCTURE VARIABLES
•If employee 1 and employee 2 belong to same
structure
then following statment is valid ;
e1=e2;
e2=e1;
•However, the statement such as:
e1==e2
e1!=e2
not permitted

9. Eg: for copying:
struct employee
{
int id;
Char name [20];
Float salary;
};
void main ()
Struct employee e1;
Struct employer e2 {02,"Joy", 1000);
e1=e2;
printf("Details of e1");
printf("%d %s %f,e1.id, e1.name,e1.salary);
}

10. Eg: for comparing:
struct employee
{
int id;
Char name [10];
Float salary;
};
void main ()
Struct employee e1{01,"ram",1000);
Struct employer e2 {02,"Joy", 2000);
If (e1.id<e2.id)
printf("Yes");
}

11. Consider a case ,where we need to store data of 3 students we can store it
by using the structure as shown below,
#include <stdio.h>
struct employee
{
int id;
Char name [20];
Float salary;
};
void main ()
{
ARRAY OF STRUCTURES

12. Struct employee e1{01,"ram",1000);
Struct employee e2 {02,"joy", 2000);
Struct employee e3{03,"roy",3000);
printf("Details of e1");
scanf("%d %c %f,e1.id, e1.name,e1.salary)
printf(Details of e2");
Scanf("%d %c %f";e2.id,e2.name,e2.salary);
printf("Details of e3");
scanf("%d %c %f",e3.id,e3.name,e3.salary);
}

13. •An array of structres in C can be defined as the collection of multiple
structures variables where each variable contains information about
different entities. The array of structures in C are used to store information
about multiple entities of different data types. The array of structures is
also known as the collection of structure.

14. Eg: struct employee
{
int id;
char name;
float salary;
}
void main ()
{
Struct employee e[3]
for(i=0;i < 3;i++)
{
scanf("%d %s %f", &e[i]. id, &e[i].name, &e[i] .salary);
for(i=0;i<3;i++)
{
printf("%d %s %f", &e[i]. id ,&e[i] .name. &e[i]. salary);
}}

15. CONCLUSION

16. THANK YOU!