@dabdab You won't get an error, because sometimes you don't need break but when you do need it and don't use it things won't work how you expect. So unless you are leaving it out because you want cases to fall through it is better to always use break (or sometimes return).
Here's an example where breaks are placed in such a way to create groups of conditions
const myValue = 1;
switch(myValue)
{
case 0:
case 1:
Console.print("My value is 0 or 1");
break;
case 20:
case 30:
Console.print("My value is 20 or 30");
break;
}
Here's an example where no breaks are used so you can tell which range a values falls within.
const myValue = 21;
switch (true)
{
case (myValue > 10):
Console.print("My value is > 10");
case (myValue > 20):
Console.print("My value is > 20");
case (myValue > 30):
Console.print("My value is > 30");
}