Introduction

I have used CodeBlocks compiler for debugging purpose. But you can use any C++ programming language compiler as per your availability.

#include <iostream>
 
using namespace std;
 
int main()
{
    int monthnumber;
 
    //Reading a month number from user
 
   cout<<"Enter month number(1-12): ";
   cin>>monthnumber;
 
    switch(monthnumber)
    {
        case 1: cout<<"31 days";
            break;
        case 2: cout<<"28 or 29 days";
            break;
        case 3: cout<<"31 days";
            break;
        case 4: cout<<"30 days";
            break;
        case 5: cout<<"31 days";
            break;
        case 6: cout<<"30 days";
            break;
        case 7: cout<<"31 days";
            break;
        case 8: cout<<"31 days";
            break;
        case 9: cout<<"30 days";
            break;
        case 10: cout<<"31 days";
            break;
        case 11: cout<<"30 days";
            break;
        case 12: cout<<"31 days";
            break;
        default: cout<<"Invalid input!!! enter month number between 1-12";
 
    }
    return 0;
 
}

Result