javascript - node.js - can someone explain this callback? -

there's more 1 node.js tutorial out there, demonstrating how create server. but, they're coded in different ways. so, how know when write 1 way, versus another? none of tutorials explain why wrote way did.

for example...

example 1:

// create http server, passing in function reason: http.createserver(function(request, response) { 

versus example 2:

// create http server, , start var server = http.createserver(handlerequest); server.listen(port, function () { 

thanks in advance. i'm having trouble understanding this.

they're no different, really. in first, you're defining function handling request on spot have start listening @ end.

http.createserver(function(request, response) {   ... }).listen(port, function() { ... }); 

in second, define function handling request elsewhere , don't use chaining.

function handlerequest(request, response) {   ... } var server = http.createserver(handlerequest); server.listen(port, function() { ... }); 

they both same thing. depends on how want write it.