how to make a switch case statement in c 2b 2b

1#include <iostream>
2using namespace std;
3int main(){
4   int num = 5;
5   switch(num + 2) {
6      case 1: 
7        cout << "Case1: Value is: " << num << endl;
8      case 2: 
9        cout << "Case2: Value is: " << num << endl;
10      case 3: 
11        cout << "Case3: Value is: " << num << endl;
12      default: 
13        cout << "Default: Value is: " << num << endl;
14   }
15   return 0;
16}