Structure is user defined datatype in C language which allows us to combine data of different types together. structure somewhat similar to the array. but array is the collection of the homogeneous elements. and structure consist of the collection of the heterogeneous elements.
For creating a structure struct keyword is used.
struct structure_name
{
data_type member1;
data_type member2;
.
.
data_typen memebern;
};
We can create the structure for a student as mentioned above as:
struct student
{
char name[50];
int Roll_No;
float Marks;
};
When a structure is defined, it creates a user-defined type but, no storage is allocated. For the above structure of student, variable can be declared as:
struct student
{
char name[50];
int Roll_No;
float Marks;
};
inside a main function
struct person s1, s2, s[20];
Another way of creating structure
struct student
{
char name[50];
int Roll_No;
float Marks;
}s1 ,s2 ,s[20];
In both cases, 2 variables s1, s2 and array p having 20 elements of type struct person are created.
There are two types of operators are used to accessing the member of structure
Any member of a structure can be accessed as:
structure_variable_name.member_name
Suppose we want access the Marks for variable s2. then it can be accessed as:
s2.Marks
There are two types of the structure initialization:
#include<stdio.h>
#include<conio.h>
struct student
{
char name[20];
int rollno;
float marks;
}s{"xyz", 4, 560};
void main()
{
clrscr();
printf("\nStudent Name\tRollno\tMarks\n");
printf("%s\t%i\t%f", s.name, s.rollno, s.marks);
printf("\n");
printf("%s\t%i\t%f",s.name,s.rollno,s.marks);
getch();
}
Output:
Student Name Rollno Marks
xyz 4 560
#include<stdio.h>
#include<conio.h>
struct student
{
char name[20];
int rollno;
float marks;
};
void main()
{
struct student s;
clrscr();
printf("Enter student Name, Rollno, Marks:\n");
scanf("%s%i%f", s.name, &s.rollno, &s.marks);
printf("\nStudent Name\tRollno\tMarks\n");
printf("%s\t%i\t%f", s.name, s.rollno, s.marks);
getch();
}
Output:
Enter student name, Rollno, marks
xyz
4
560
Student Name Rollno Marks
xyz 4 560
#include<stdio.h>
#include<conio.h>
struct cricket
{
char name[20];
int age;
int score;
};
void main()
{
int i;
struct cricket c[2];
clrscr();
for(i=0;i<2;i++)
{
printf("Enter the name of the player:");
scanf("%s",c[i].name);
printf("Enter age:");
scanf("%d",&c[i].age);
printf("Enter score in ODI:");
scanf("%d",&c[i].score);
}
printf("Entered data is:\n");
for(i=0;i<2;i++)
{
printf("Name of the player:%s\n",c[i].name);
printf("Age:%d\n",c[i].age);
printf("Score in ODI:%d\n",c[i].score);
}
getch();
}
Output:
Enter the name of the player:
abc
Enter age:
20
Enter score in ODI:
750
Enter the name of the player:
xyz
Enter age:
22
Enter score in ODI:
678
Entered data is:
Name of the player:abc
Age:20
Scorein ODI:750
Entered data is:
Name of the player:xyz
Age:22
Scorein ODI:678
There are three methods to pass structure to function
#include<stdio.h>
#include<conio.h>
struct student
{
char name;
int rollno;
float marks;
};
struct student std_func(char, int, float);
int main()
{
struct student s1 = {'xyz', 10, 570};
clrscr();
std_func(s1.name, s1.rollno, s1.marks);
getch();
}
struct student std_func(char name, int rollno, float marks)
{
printf("Name\tRoll No.\tMarks\n");
printf("%c\t%d\t\t%f", name, rollno, marks);
}
Output:
Name Roll No. Marks
xyz 10 570.000000
#include<stdio.h>
#include<conio.h>
void modify(struct student s);
struct student
{
int roll_no;
float marks;
};
void main()
{
struct student s;
clrscr();
printf("\nEnter roll_no and marks:\n");
scanf("%d%f", &s.roll_no, &s.marks);
modify(s);
printf("\nafter modificattion in main:\n");
printf("%d\t%2f", s.roll_no, s.marks);
getch();
}
void modify(struct student s)
{
printf("\nmodify the marks");
scanf("%f",&s.marks);
printf("\nafter modificattion in function:\n");
printf("%d\t%2f", s.roll_no,s.marks);
}
Output:
Enter roll_no and marks:
2
70.40
modify the marks89.90
after modificattion in function:
1 89.900000
after modificattion in main:
1 70.400000
| Basis for Comparison | Array | Structure |
|---|---|---|
| Basic | An array is a collection of variables of same data type. | A structure is a collection of variables of different data type. |
| Syntax | Syntax type array_name[size] | struct sruct_name{ type element1; type element1; . . } variable1, variable2, . .; |
| Memory | Array elements are stored in contiguous memory location. | Structure elements may not be stored in a contiguous memory location. |
| Access | Array elements are accessed by their index number. | Structure elements are accessed by their names. |
| Operator | Array declaration and element accessing operator is "[ ]" (square bracket). | Structure element accessing operator is "." (Dot operator). |
| Pointer | Array name points to the first element in that array so, array name is a pointer. | Structure name does not point to the first element in that structure so, structure name is not a pointer. |
| Size | Every element in array is of same size. | Every element in a structure is of different data type. |
| Keyword | There is no keyword to declare an array. | "struct" is a keyword used to declare the structure. |
| User-defined | Arrays are not user-defined they are directly declared | Structure is a user-defined datatype. |