In this lab, we will create a menu-driven program using switch case in C. A menu-driven program is a program that presents a menu to the user, and the user chooses an option from the menu to perform a specific task. In this program, we will create a menu that will allow the user to perform various tasks such as calculating the factorial of a number, checking if a number is prime or composite, and checking if a number is even or odd.
The first step is to create a new C file in the ~/project/ directory. Name this file main.c.
In this step, we will include the standard input and output library in our program. This library provides functions for input and output operations in C.
#include <stdio.h>main() functionmain() is the entry point function in a C program. In this step, we will define the main() function.
int main()
{
// Code goes here
return 0;
}In this step, we will display the menu to the user. The menu will allow the user to choose from different options. For this program, we will use the following options:
int main()
{
printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
int choice, num, i;
unsigned long int fact;
while(1)
{
printf("1. Factorial \n");
printf("2. Prime\n");
printf("3. Odd\\Even\n");
printf("4. Exit\n\n\n");
printf("Enter your choice : ");
scanf("%d",&choice);
}
return 0;
}In this step, we will implement the switch case statement. Based on the user's choice, we will execute different cases.
int main()
{
printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
int choice, num, i;
unsigned long int fact;
while(1)
{
printf("1. Factorial \n");
printf("2. Prime\n");
printf("3. Odd\\Even\n");
printf("4. Exit\n\n\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:
/*
* Code to calculate factorial of a number
*/
break;
case 2:
/*
* Code to check if a number is prime or composite
*/
break;
case 3:
/*
* Code to check if a number is even or odd
*/
break;
case 4:
/*
* Code to exit the program
*/
break;
}
}
return 0;
}In this step, we will calculate the factorial of a number requested by the user when the user selects option 1.
int main()
{
printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
int choice, num, i;
unsigned long int fact;
while(1)
{
printf("1. Factorial \n");
printf("2. Prime\n");
printf("3. Odd\\Even\n");
printf("4. Exit\n\n\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:
printf("Enter number:\n");
scanf("%d", &num);
fact = 1;
for(i = 1; i <= num; i++)
{
fact = fact*i;
}
printf("\n\nFactorial value of %d is = %lu\n\n\n",num,fact);
break;
case 2:
/*
* Code to check if a number is prime or composite
*/
break;
case 3:
/*
* Code to check if a number is even or odd
*/
break;
case 4:
printf("\n\n\t\t\tCoding is Fun !\n\n\n");
exit(0);
}
}
return 0;
}In this step, we will check if a number is prime or composite. The program will output a message indicating whether the number entered by the user is prime or not.
int main()
{
printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
int choice, num, i;
unsigned long int fact;
while(1)
{
printf("1. Factorial \n");
printf("2. Prime\n");
printf("3. Odd\\Even\n");
printf("4. Exit\n\n\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:
/*
* Code to calculate factorial of a number
*/
break;
case 2:
printf("Enter number:\n");
scanf("%d", &num);
if(num == 1)
printf("\n1 is neither prime nor composite\n\n");
for(i = 2; i < num; i++)
{
if(num%i == 0)
{
printf("\n%d is not a prime number\n\n", num);
break;
}
}
/*
Not divisible by any number other
than 1 and itself
*/
if(i == num)
{
printf("\n\n%d is a Prime number\n\n", num);
break;
}
break;
case 3:
/*
* Code to check if a number is even or odd
*/
break;
case 4:
printf("\n\n\t\t\tCoding is Fun !\n\n\n");
exit(0);
}
}
return 0;
}In this step, we will check if a number is even or odd. The program will output a message indicating whether the number entered by the user is even or odd.
int main()
{
printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
int choice, num, i;
unsigned long int fact;
while(1)
{
printf("1. Factorial \n");
printf("2. Prime\n");
printf("3. Odd\\Even\n");
printf("4. Exit\n\n\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:
/*
* Code to calculate factorial of a number
*/
break;
case 2:
/*
* Code to check if a number is prime or composite
*/
break;
case 3:
printf("Enter number:\n");
scanf("%d", &num);
if(num%2 == 0) // 0 is considered to be an even number
printf("\n\n%d is an Even number\n\n",num);
else
printf("\n\n%d is an Odd number\n\n",num);
break;
case 4:
printf("\n\n\t\t\tCoding is Fun !\n\n\n");
exit(0);
}
}
return 0;
}In this step, we will add a case to exit the program when the user selects option 4.
int main()
{
printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
int choice, num, i;
unsigned long int fact;
while(1)
{
printf("1. Factorial \n");
printf("2. Prime\n");
printf("3. Odd\\Even\n");
printf("4. Exit\n\n\n");
printf("Enter your choice : ");
scanf("%d",&choice);
switch(choice)
{
case 1:
/*
* Code to calculate factorial of a number
*/
break;
case 2:
/*
* Code to check if a number is prime or composite
*/
break;
case 3:
/*
* Code to check if a number is even or odd
*/
break;
case 4:
printf("\n\n\t\t\tCoding is Fun !\n\n\n");
exit(0);
}
}
return 0;
}In this lab, we have created a menu-driven program in C using switch case. This program displays a menu to the user, and the user can choose from different options to perform various tasks such as calculating the factorial of a number, checking if a number is prime or composite, and checking if a number is even or odd. We hope this lab has provided you with a good understanding of creating a menu-driven program using switch case in C.