Control Flow: if and for

Part of the Go course

So far every program you have written runs top to bottom, one line after another, with no choices along the way. Real programs need to react: charge a different shipping rate for a big order, print a different message for an adult than for a minor, keep asking a server for a response until one arrives.

Think of if the way you would think of a fork in a hallway with a sign on it: if a condition is true, go one way, otherwise go the other. Here is the smallest version ...