Question

1. Write a program that takes a number as input and check whether the number is positive, negative or zero.

2. Write a C++ program that prompts the user to enter a number and checks whether the entered number is even or odd.

3.  Using switch-case statement write a C++ program that prompts the user to enter 1, 2 or 3 and display "Red" if selection is 1, "Yellow" if selection is 2, or "Green" if selection is 3.

4. Write a program that takes a number as input and prints its multiplication table up to 10.

5. Write a function to read an integer n and print the factorial of n.

Answer 1

1.

Code:

#include<iostream>
using namespace std;
int main(){
   int num;
   cout << "Enter a number: ";
   cin >> num;
   if(num > 0){
       cout << "The entered number is positive." << endl;
   }
   else if(num < 0){
       cout << "The entered number is negative." << endl;
   }
   else{
       cout << "The entered number is zero." <<endl;
   }
}
Output:

Explanation:

2.

Code:

#include<iostream>
using namespace std;
int main(){
   int num;
   cout << "Enter a number: " ;
   cin >> num;
   if(num % 2 == 0){
       cout << num << " is an even number." << endl;
   }
   else{
       cout << num << " is an odd number." << endl;
   }
}

Output:

Explanation:

3.

Code:

#include<iostream>
using namespace std;
int main(){
   int choice;
   cout << "Enter a number 1, 2 or 3" << endl;
   cin >> choice;
   switch(choice){
       case 1:
           cout << "Red" << endl;
           break;
       case 2:
           cout << "Yellow" << endl;
           break;
       case 3:
           cout << "Green" << endl;
           break;
       default:
           cout << "Invalid choice" << endl;
           break;
   }
}

Output:

Explanation:

4.

Code:

#include<iostream>
using namespace std;
int main(){
   int num, i;
   cout << "Enter a number: ";
   cin >> num;
   for(i=1; i<=10; i++){
       cout << num << " * " << i << " = " << num * i << endl;
   }
}

Output:

Explanation:

5.

Code:

#include<iostream>
using namespace std;
int factorial(int n);
int main(){
   int n, result;
   cout << "Enter a number: ";
   cin >> n;
   result = factorial(n);
   cout << result << endl;
}
int factorial(int n){
   if(n < 0){
       return 0;
   }
   else if(n == 0){
       return 1;
   }
   else{
       return n*factorial(n-1);
   }
}
Output:

Explanation: