CODEWITHSUNDEEP
javascriptcallback
equaliser
equaliser

Reputation: 171

Get Value out of Callback

I have a callback, where I need to get the array out of my callback.

I am trying to return the awaited array into the predefined one. 

let documents = [];

  socket.on('echo', async function(documents, data){
    documents = await data;
    console.log(documents); // shows me, what I want to see
  });

  console.log(documents); // empty Array

I need the result in my predefined Array documents

I have read several Tuts, but I dont get it. I know on stackoverflow it is sked several times. But all threads seem to be more complex then my situation. So I hope to get it cleared out with an more incomplex one.

Upvotes: 0

Views: 68

Answers (3)

emcee22
emcee22

Reputation: 1889

You need to understand something first. When this runs what is inside the callback doesn't run unit the server will emit that event, in your case 'echo'.

What I think you want to do is use documents outside the callback. You can create a function and call it when the event is emitted.

Something like this:

const manageDocuments = (documents) => {
    // do what you want with documents array
    console.log(documents);
}

socket.on('echo', async function(documents, data){
    documents = await data;
    manageDocuments(documents);
});

Of course you can also get rid of the async/await

Upvotes: 2

Joaquín Romero Franco
Joaquín Romero Franco

Reputation: 158

The problem is that the code outside the socket function executes with the empty array because is only executed once at runtime.

If you want to have access to the documents inside the socket function you have to make then persist, or use the socket.on inside of another loop.

Upvotes: 1

Idan
Idan

Reputation: 4023

let documents = await socket.on('echo', async function(documents, data){
    console.log(documents); 
    return data; 
  });

console.log(documents);

Upvotes: 2

Related Questions