In JavaScript, should I be using return with callbacks? [duplicate]

Question

In the code here the first example just does callbacks, the second example does "return callback".

Under what circumstances should I do "return callback" instead of just "callback"?

this.listRegions((err, regions) => {
  if (err) {
    callback(err)
  } else {
    callback(null, regions)
  }
})

OR

this.listRegions((err, regions) => {
  if (err) {
    return(callback(err))
  } else {
    return(callback(null, regions))
  }
})

You return something whenever you expect a value from a function call. — Sebastian Simon
– Sebastian Simon, Commented Feb 27, 2016 at 3:40
This question has already been asked and answered, but I cannot track it down now. The simple answer is (usually) "no". You can use return in order to get out of the function, though, as a kind of shorthand for callback(null, regions); return. For instance, in the second sample code you show, this would allow you to eliminate the else part. BTW, the parens are not required around the return value and many popular style guides call for you not to use them. — user663031
– user663031, Commented Feb 27, 2016 at 3:49

Afanasii Kurakin · Accepted Answer · 2016-02-27 03:49:45Z

0

It's useful to break out from the function earlier, without extra braces and conditional statements:

this.listRegions((err, regions) => {
  if (err)
    return callback(err)
  callback(null, regions)
})

answered Feb 27, 2016 at 3:49

Afanasii Kurakin

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