Functions

A function is a reusable block of code.

Think of it as a recipe you can call again and again.

You declare it with func.

You list inputs with names and types. You may return a result.

Declaring and calling

Write func, a name, parentheses, then braces.

Call it by writing the name and passing values.

Parameters and return types

Parameter types come after names.

If several parameters share a type, write the type once at the end of the group.

Put the return type after the parentheses.

Named return values

You can name return parameters. A bare return then sends those named values back.

That can make longer functions easier to follow.

Variadic parameters

A parameter like nums ...int accepts zero or more ints.

Inside the function it becomes a stretchy list.

Why functions help

Functions stop copy-paste.

Name them after what they do.

Small recipes are easier to test and reuse.

Next lesson: Go's big idea of returning more than one value.