Closures Inside Callbacks

Question

Closures are functions that inherit variables from their enclosing environment. So lets see this code:

binaryServer = BinaryServer({port: 9001});

binaryServer.on('connection', function(client) {
  console.log("new connection");

  client.on('stream', function(stream, meta) {
    stream.on('data', function(data){
    //actions
    });
    stream.on('end', function() {
    //actions
    });
  });
});

So, I am correct if I say: " function(data){//actions} is a closure because inherits the variables of enclosing environment (like the object client) "? Because of my experiences that's what happening.

You might also hear that a function "closes over" a particular variable. — zzzzBov, Dec 07 '15 at 20:08
The usual JS `this` caveats apply, e.g., `this` in the closure won't be the `this` in its definition context. — Dave Newton, Dec 07 '15 at 20:17

score 2 · Accepted Answer · answered Dec 07 '15 at 20:06

2

Yes, that would be correct to say.

answered Dec 07 '15 at 20:06

Madara's Ghost

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thanks for the confirmation – carduh Dec 07 '15 at 20:11

score 1 · Answer 2 · edited May 23 '17 at 12:23

1

Yes, You are correct.

Closures are functions that refer to independent (free) variables. In other words, the function defined in the closure 'remembers' the environment in which it was created.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures

How do JavaScript closures work?

edited May 23 '17 at 12:23

Community

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answered Dec 07 '15 at 20:14

Scarecrow

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Closures Inside Callbacks

2 Answers2