Structure data type ~ whereisstuff

Structure:

It is used to store different data items under a common name.
It is opposite to the array because the array stored only similar data items.

Rules:

A structure must end with a semicolon.
Usually, a structure appears at the top of the main program.
Each structure must be terminated.
The structure variables must be accessed with structure variable with the dot operator.

Syntax:

struct structure_name

{

data_type variable_name 1;

data_type variable_name 2;

.................................

.................................

data_type variable_name n;

};

struct structure_name short_name;

Example program structure:

#include<stdio.h>

#include<conio.h>

//Structure declaration

struct std

{

int roll_num,t,e,m,s,so,tot;

char name[30];

float avg;

};

struct std s;//strucure short name declare

void main()

{

clrscr();

printf("\nEnter student roll number : ");

scanf("%d",&s.roll_num);//calling structure varaiable via strcure

short name

printf("\nEnter student name : ");

scanf("%s",&s.name);

printf("\nEnter student five subject mark: ");

scanf("%d %d %d %d %d",&s.t,&s.e,&s.m,&s.s,&s.so);

s.tot=s.t+s.e+s.m+s.s+s.so;

printf("\nTotal mark: %d ",s.tot);

s.avg=s.tot/5;

printf("\nAverage mark: %f ",s.avg);

getch();

}

Output:

User defined data types:

‘C’ provides a capability that enables the programmer to assign an alternate name to a data type.

This is done with a statement known as a typedef.

Syntax:

typedef type dataname;

dataname short_name;

Example program for typedef:

#include<stdio.h>

#include<conio.h>

#define D 7

void main()

{

typedef int weeks;//declare typedef

weeks wk;//new datatype called weeks

clrscr();

printf("\nEnter weeks:");

scanf("%d",&wk);

printf("\nThe number of days %d in %d weeks",wk*D,wk);

getch();

}

Output:

Nested structure:

If a structure contains more than one structure as its members, is known as a nested structure i.e. structure within another structure.
It is used to reliability of the program by reading the complexity.

Note: Members are nothing but, if variables are function inside of the main program called members.

Syntax for nested structure members can be accessed as:

Outer_structure_name.inner_strucure_name.inner_structure_member

Example program for if:

/* Write a C program detail about emloyee*/

#include<stdio.h>

#include<conio.h>

void main()

{

int expe=2020;//To calculate working experience

struct date//Inner structure

{

int day,year;

char month[20];

};

struct employee//outer structure

{

int emp_id,salary;

char name[30];

struct date doj;//date strcture defined in outer structure

};

struct employee emp;

clrscr();

printf("\nEnter employee id: ");

scanf("%d",&emp.emp_id);

printf("\nEnter employee name: ");

scanf("%s",&emp.name);

printf("\nEnter employee salary: ");

scanf("%d",&emp.salary);

printf("\nEnter date of joining: ");

//Nested structure of members calling

scanf("%d %s %d",&emp.doj.day,&emp.doj.month,&emp.doj.year);

printf("\nEmployee Name : %s",emp.name);

printf("\nEmployee Employee id: %d",emp.emp_id);

printf("\nEmployee Salary : %d",emp.salary);

printf("\nEmployee DOJ : %d %s %d ",emp.doj.day,emp.doj.month,

emp.doj.year);

expe=expe-emp.doj.year;

printf("\nWorking experience %d years",expe);

getch();

}

Output: