Menu Driven Program in C++

//__ Let me demostrate you how to make menu :D :D :D :D

#include<iostream>

#include<conio.h>

#include<stdlib.h>      //__ system("cls")

using namespace std;

char prime_number(int number);

void prime_function();

void factorial_function();

int fact(int number);

int add_number();

int main()

{

      int choice = 0;

      cout << "\n\n\n\t\t\t __ Menu __ ";

      cout << "\n\n\t\t1. Factorial of a Number";

      cout << "\n\n\t\t2. Prime Number between 1 to 50";

      cout << "\n\n\t\t3. Sum of first 10 Numbers";

      cout << "\n\n  Enter your good choice Mam - ";

      cin >> choice;

      switch(choice)

      {

      case 1: system("cls");  //__ To clear the screen ___

                  factorial_function();

                  break;

      case 2: system("cls");

                  prime_function();

                  break;

      case 3: system("cls");

                  cout << "\n\n\t\t__ Add numbers from 1 to 10\n\n  Result - ";

                  cout << add_number();

                  break;

      }

      //__ lets start

      getch();

      return 0;

}

void prime_function()

{

      int counter = 0; 

      char result;

      cout << "\n\n\t\t ___  Prime numbers between 1 to 50  ____\n\n\n\n  Prime Number - \n\n  ";

      for(counter = 1; counter <= 50; counter++)     

      {

            result = prime_number(counter);    

            if (result == 'Y')     

            {

                  cout << counter << " , ";

            }

      }

      cout << "\b\b  ";

      getch();

}

char prime_number(int number)

{

      int counter = 1, count = 0;

      while(counter < number)

      {

            if ((number % counter) == 0)

            {

                  count++;

            }

            counter++;

      }

      if (count == 1)

      {

            return 'Y';

      }

      else

      {

            return 'N';

      }

}

void factorial_function()

{

      int num,fac;     

      cout<<"\n\n\t ________Factorial of A Number_______\n\n";

     

      cout << "  Enter the Number  -  ";

     

      cin>>num;

     

      fac=fact(num);

     

      cout<<"\n\n\t  Factorial of " << num << " is " << fac << "\n";

      getch();

}

int fact(int number)

{

            //int result=1;

            // if(number < 1)

            // {

            //    cout<< "\n\n\t\t Please enter Positive Integer";

            // }

            // else

            // {

            //    for(int i=1;i<=number;i++)  

            //    {

            //          result=result*i;

            //    }

            // }

            // return result;

      if (number == 1)

      {

            return 1;

      }

      else

      {

            return number * fact(number - 1);

      }

}

int add_number()

{

      int number = 1, sum = 0;

      for(number = 1; number <= 10; number++)

      {

            sum = sum + number;

      }

      return sum;

}