How do I convert a series of if statements testing ranges into a switch?

January 19, 2024

this my if condition code, but I can’t convert it.

    #include <iostream>
using namespace std;
int main()
{
  int num;
  cout << "please enter a number: ";
  cin >> num;

  if (num == 10)
  {
    cout << "Case 1";
  }
  else if (num > 19 && num < 21)
  {
    cout << "Case 2";
  }
  else if (num > 29 && num < 33)
  {
    cout << "Case 3";
  }
  else
  {
    cout << "Invalid Number";
  }
  return 0;
}

what I tried to do was this:

    switch (num)
{
case 1:
 num==10;
  cout << "Case 1";
  break;
case 2: 
  num > 19 && num < 21;
  cout << "Case 2";
  break;
case 3:
  num> 29 && num < 33;
  cout << "Case 3";
  break;
default:
 cout << "Invalid Number";
}

it Ignores my condition and if I put my condition in place of "case 1" it gives me an error.

so , what can I do?

>Solution :

A switch only selects individual values, but you can use case fall-through to let it combine multiple values. In your example, there aren’t that many in the chosen ranges, so it might be appropriate:

switch (num)
{
case 10:
  cout << "Case 1";
  break;
case 20:
  cout << "Case 2";
  break;
case 30:
case 31:
case 32:
  cout << "Case 3";
  break;
default:
 cout << "Invalid Number";
}