Variables & Constant In C With Real Life Example

Variable:

Variable is an entity whose value can vary (i.e. change) during execution of a program.

 int a = 20;

#include<stdio.h>
main()
{
printf("********* Example Variable *********\n");
int i, j;
i = 10; j = 20;
printf("\n value of i=%d & j=%d \n",i, j);
// change the value of variable
printf("\n change value of variable ");
i = 50;
printf("\n After changing value of variable i is : %d \t", i);
getch();
}

Real life example of variable

 

• Everyone has a saving / current bank account. From this account you can withdraw money from ATM or deposit money by visiting the bank.
  
  
  
  
  

Constant:

Constant is an entity whose value cannot be changed throughout the execution of program.

const int j = 50;

#include<stdio.h>
main()
{
printf("********* Example Constant *********\n");
const int i = 100;
printf("\n value of constant i= %d \n",i);
i = 50;
printf("\n%d \t", i);
getch();
}

Output: Will give an error because we cannot change the value of constant variable.

#include<stdio.h>
main()
{
printf("********* Example Constant *********\n");
const int i ;
printf("\n value of constant i= %d \n",i);
//i = 50;
printf("\n%d \t", i);
getch();
}

Real life example of constant

• Now suppose we want to create a fixed deposit in bank. This is done to keep a particular amount locked for some specific period.
  
  
  

Summary:

This article will help fresher candidates to understand Variables & Constants  in C with Real Life Example.