Functions ​

fn declares a function. Parameters can have default values, and callers can name arguments:

fn greet(name, greeting = "Hello") {
    return `${greeting}, ${name}!`;
}

print(greet("Ada"));
print(greet("Alan", greeting: "Hi"));

A function without a name is a lambda: fn(x) => x * 2 for one expression, or fn(x) { ... } with a body. Functions are values you can store and pass around, and they remember the variables around them (closures).

Your turn ​

Write makeCounter(), which returns a function that counts up by one each time it is called.