Challenge 3 — Solution

Task: Write a switch statement that takes a variable holding a month
number (1-12) and echoes the correct season ("Winter", "Spring",
"Summer", "Autumn") — group multiple case labels together for months
sharing a season, using fall-through deliberately.

<?php
    $month = 7;

    switch ($month) {
        case 12:
        case 1:
        case 2:
            echo "Winter";
            break;
        case 3:
        case 4:
        case 5:
            echo "Spring";
            break;
        case 6:
        case 7:
        case 8:
            echo "Summer";
            break;
        case 9:
        case 10:
        case 11:
            echo "Autumn";
            break;
        default:
            echo "Not a valid month number";
    }
?>


Output (for $month = 7):
Summer

Notes:
- Stacking case labels with no code between them (e.g. case 12: case
  1: case 2:) is exactly the deliberate use of fall-through mentioned
  in the chapter - execution "falls through" each empty case straight
  down to the first one that actually has a body, so all three months
  share the same "Winter" output.
- Every case still needs its own break at the end of its real code
  block, or execution would keep falling through into the next
  season's own case too.
- The default case handles anything outside 1-12, so the switch
  behaves sensibly even for genuinely invalid input.