Structure in C Programming- Basic Concepts

Structure-Basic Concepts, Array within structure, Array of structure

1. Structures in C
Dr. Mary Jacob
Asst.Professor, Department of Computer Science
Kristu Jayanti College,Autonomous
Bengaluru

2. What is a Structure?
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A structure is a user-defined data type in C that groups related variables of
different data types under a single name.
- Each variable in the structure is called a member or field.
Purpose of Structures
vOrganize related data:
Helps in grouping different types of data together, such as details of a
student (name, roll number, marks)
vCode clarity and efficiency:
Avoids multiple variables for different attributes of the same entity.

3. Use Cases of Structures
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vStudent Record: Structure to store student details such as roll
number, name, and marks.
vEmployee Record: Structure to store employee information such as
ID, name, department, salary, etc.
vDate Structure: Structure to represent date with members for day,
month, and year.

4. Defining a Structure?
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Syntax:
struct StructureName
{
dataType member1;
dataType member2;
...
};
Example:
struct Student
{
int roll_no;
char name[50];
float marks;
};
Østruct keyword is used to define a structure.
ØStructureName is the name of the structure.

5. Array within a Structure
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A structure can contain arrays as its members, which allows for grouping
multiple values of the same type.

Syntax:
struct StructureName
{
dataType member1;
dataType member2;
...
};
Example:
struct Student
{
int roll_no;
char name[50];
float marks;
};

6. Declaring Structure variables
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struct StructureName variable name
Example:
struct Student s1;

7. Accessing Structure Members
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Dot Operator (.) - Used to access structure members.
Example:
printf("%d", s1.roll_no); // Accessing roll_no of student s1
printf("%s", s1.name); // Accessing name of student s1
printf("%.f", s1.marks); // Accessing marks of student s1

8. Array of Structures
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An array of structures is an array where each element is a structure.This allows
you to store multiple records of a structure type in an array.
Syntax:
struct StructureName
{
dataType member1;
dataType member2;
...
};
struct StructureName arrayName[size];
Example:
struct Student
{
int roll_no;
char name[50];
float marks;
};
struct Student students[3]; // Array of structures

9. Example
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#include <stdio.h>
struct Student
{
int roll_no;
char name[50];
float marks;
};
void main()
{
struct Student students[2] =
{
{101, "John", 85.5},
{102, "Jane", 90.0}
};


for(int i = 0; i < 2; i++)
{
printf("Roll No: %d\n", students[i].roll_no);
printf("Name: %s\n", students[i].name);
printf("Marks: %.2f\n", students[i].marks);
printf("\n");
}
}

10. Summary
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üA structure in C allows grouping multiple data types into one
unit.
üStructures are useful for representing real-world entities and
organizing complex data.
üThe key operations with structures include declaration,
initialization, accessing members, and using pointers.
üStructures can be nested or used in arrays.

11. THANKS