Methods

A method is a function with a receiver.

The receiver is the type the method belongs to, often a struct.

Think of it as giving your form special buttons it can press.

Methods let you attach actions to your data without a class tree.

Value receivers

With a value receiver, the method gets a copy.

That is good for reading fields.

It is also good for returning new values without changing the original.

Pointer receivers

Use a pointer receiver when the method should update the value: func (r *Rect) Scale(...).

Also use it when copying a big struct would be slow.

The method gets the house address, not a copy of the whole house.

Calling methods

Use a dot: value.Method().

Go can take an address for you when needed.

So c.Inc() still works even if Inc wants a pointer.

Methods on non-struct types

You can define methods on any named type in the same package.

Even aliases of built-ins work.

The type just cannot come from another package.

Stay consistent

If any method needs a pointer receiver, use pointer receivers for that type's methods.

Mixed styles confuse readers.

If one method needs a pointer receiver, prefer pointer receivers for that type.