Difference between http.Handle and http.HandleFunc?

Question

The Go docs have the following example for the http package:

http.Handle(\"/foo\", fooHandler)
http.HandleFunc(\"/bar\", func(w http.ResponseWriter, r *http.         


        

Answer 1

No It's Different. Let's Examine

func Handle(pattern string, handler Handler) {
    DefaultServeMux.Handle(pattern, handler) 
}

handle expects us to pass a Handler. Handler is an interface

type Handler interface {
    ServeHTTP(ResponseWriter, *Request)
}

if any type implements ServeHTTP(ResponseWriter, *Request) for example: myCustomHandler then we can pass it like Handle(pattern string, myCustomHandler).

In the second scenario:

HandleFunc(pattern string, func(w ResponseWriter, r *Request) {
    // do some stuff
}

HandleFunc expects a function where Handle expects a Handler interface.

So, if you just want to pass a function then you can use http.HandleFunc(..). Like @David showed that behind the scenes it implements Handler interface by calling ServeHTTP.

type HandlerFunc func(ResponseWriter, *Request)

// ServeHTTP calls f(w, r).
func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
    f(w, r)
}