Curriculum Types & methods Methods exercise 4 · fill-word
Methods
Make the receiver a POINTER receiver so bump can mutate the
caller's Counter. The blank is the type-side modifier.
Without it, bump takes a copy and the mutation is invisible
to main — same as exercise 6 of theme 3.1, now method-shaped.
TypeScript reference
Fill the blanks →
About this theme
Methods are functions with a receiver — a special argument declared before the function name: func (r Receiver) Foo() { ... }. Two flavours: value receivers (operate on a copy) and pointer receivers (operate on the original). The rule of thumb: use a pointer receiver if you'd modify the receiver, or if the receiver is large enough that copying is wasteful.