What is the difference between parameter and receiver

Question

I am following a Go tutorial and am stuck as I cant understand a particular method signature:

func (p *Page) save() error {
    filename := p.Title + \".txt\         


        

Answer 1

The receiver is just a special case of a parameter. Go provides syntactic sugar to attach methods to types by declaring the first parameter as a receiver.

For instance:

func (p *Page) save() error

reads "attach a method called save that returns an error to the type *Page", as opposed to declaring:

func save(p *Page) error

that would read "declare a function called save that takes one parameter of type *Page and returns an error"

As proof that it's only syntactic sugar you can try out the following code:

p := new(Page)
p.save()
(*Page).save(p)

Both last lines represent exactly the same method call.

Also, read this answer.

Answer 2

The receiver is the object on what you declare your method.

When want to add a method to an object, you use this syntax.

ex: http://play.golang.org/p/5n-N_Ov6Xz