Programming Fundamentals › Programming Basics

Switch / Match

Choosing between many branches based on a value.

Also known as: switch case, match statement, case statement

A switch (or match) statement chooses one of many branches based on the value of a single expression. It’s a tidier alternative to a long if / else if chain.

switch (status) {
  case "paid":
    ship();
    break;
  case "pending":
  case "processing":          // two values, one branch
    wait();
    break;
  default:
    reject();
}

match status:                  # Python 3.10+
    case "paid":
        ship()
    case "pending" | "processing":
        wait()
    case _:                    # default
        reject()

The classic bug: fall-through

In C, Java and JavaScript, a case without break keeps running into the next one:

case "paid":
  ship();          // forgot break: continues into the next case
case "pending":
  wait();

Python’s match and many newer languages don’t fall through.

Habits

• Always include a default, to handle values you didn’t expect.
• Use it for fixed sets of values (enum, status). For ranges and complex conditions, if is clearer.
• Consider a lookup table when each case just returns a value:

SHIPPING = {"standard": 4.99, "express": 12.99}
fee = SHIPPING[method]

• A growing switch on type is a sign to use polymorphism instead, so each type carries its own behavior.
• Newer match statements can destructure values and check shapes (pattern matching).