Structures in C Programming

There are various types of data type such as int, char float etc.

For example:

int i; here variable i can store only data of integer type

char c; here variable c can store only data of character type

float f; here variable f can store only data of floting-point type

Variable of each data type can store only single type of data.

But, if we want to store different type of data in a single variable then we use structure variable.

“structure” is user defined data type that allows to store data items of different data type.

Defining a Structure

We can create a structure, by using the struct keyword.

The struct keyword defines a user defined new data type that can hold more than one member of different data type.

Format of structure is as follows

struct structure_name 
{
      member definition;
      member definition;
       ...
      member definition;
} [one or more structure variables];

In a C programming Structures are used to represent a record. Suppose you want to store the information of a school student such as : −

Name
Class
Section
Roll Number

Example:

struct Student 
{		char  name[50];
   		int  class;
   		char  section[100];
   		int  rollno;
} s1,s2;

Here s1 and s2 are the structure variable.

Another way of creating a structure variable is:

struct Student 
{		char  name[50];
   		int  class;
   		char  section[100];
   		int  rollno;
}
int main()
{
      struct Student s1, s2;
      return 0;
}

Example: Write a program to store and print the following information such as name, roll number, class and section of the student using structure.

#include

struct Student
{	char  name[30];
              char section[1];
	int  rollno;
	int Class;

}s1;

int main()
{	printf("Enter the name, rollno, class & section of student");
	scanf("%s", &s1.name); 
    scanf("%d", &s1.rollno);
    scanf("%d", &s1.Class);
    scanf("%s",&s1.section);
    
    printf("\n Student details");
    printf("\n Name = %s", s1.name);
    printf("\n Rollno = %d", s1.rollno);
    printf("\n Class = %d", s1.Class);
    printf("\n Section = %s",s1.section);
          
          return 0;
}

OUTPUT

Enter the name, rollno, class & section of student
Aditya				// enter by user
23456				// enter by user
12				// enter by user
A				// enter by user
 Student details
 Name = aditya
 Rollno = 23456
 Class = 12
 Section = A

Example: Write a program to store and print the following information such as name, roll number, class and section of 2 students using structure.

#include

struct Student {
    char name[30];
    char section[1];
    int rollno;
    int Class;

}
s1, s2;

int main() {
    printf("Enter the name, rollno, class & section of 1st student");
    scanf("%s", & s1.name);
    scanf("%d", & s1.rollno);
    scanf("%d", & s1.Class);
    scanf("%s", & s1.section);

    printf("Enter the name, rollno, class & section of 2st student");
    scanf("%s", & s2.name);
    scanf("%d", & s2.rollno);
    scanf("%d", & s2.Class);
    scanf("%s", & s2.section);

    printf("\n 1st  Student details");
    printf("\n Name = %s", s1.name);
    printf("\n Rollno = %d", s1.rollno);
    printf("\n Class = %d", s1.Class);
    printf("\n Section = %s", s1.section);

    printf("\n 2nd  Student details");
    printf("\n Name = %s", s2.name);
    printf("\n Rollno = %d", s2.rollno);
    printf("\n Class = %d", s2.Class);
    printf("\n Section = %s", s2.section);

    return 0;
}

OUTPUT

Enter the name, rollno, class & section of  1st  student
aditya				// enter by user
23456				// enter by user
12				// enter by user
A				// enter by user

Enter the name, rollno, class & section of  2nd  student
rajeev				// enter by user
11111				// enter by user
9				// enter by user
B				// enter by user
 
1st  Student details
 Name = aditya
 Rollno = 23456
 Class = 12
 Section = A
 
2nd  Student details
 Name = rajeev
 Rollno = 11111
 Class = 9
 Section = B

Example: Write a program to add two distances which is in feet and inches using structure.

#include 

struct Distance {
    int feet;
    float inch;
};

int main() {
    struct Distance d1, d2, sum;

    printf("Enter 1st distance");
    printf("\n Enter feet: ");
    scanf("%d", & d1.feet);

    printf("\n Enter inch: ");
    scanf("%f", & d1.inch);
    printf("\n Enter 2nd distance\n");

    printf("\n Enter feet: ");
    scanf("%d", & d2.feet);

    printf("\n Enter inch: ");
    scanf("%f", & d2.inch);

    sum.feet = d1.feet + d2.feet; // add feet

    sum.inch = d1.inch + d2.inch; // add inches

    while (sum.inch >= 12) //  if inch is greater than 12,change inch to feet 
    {
        ++sum.feet;
        sum.inch = sum.inch - 12;
    }

    printf("\n Sum of distances = %d %f ", sum.feet, sum.inch);
    return 0;
}

OUTPUT

Enter 1st distance
 Enter feet: 	
6
 Enter inch: 
8.8 
 Enter 2nd distance
 Enter feet:
4 
 Enter inch:
7.9 
 Sum of distances = 13 3.500000