Trying to understand Callback function

Question

I'm creating a simple callback function trying to understand how it works.

function cbFunction(x, y, z) {
  return x + y + z
}

function caller(x, y, z, cbFunction) {
  console.log('In caller function!')
  // your code here
  if (typeof cbFunction === "function") {
    cbFunction (x, y, z)
  }
}

caller(1, 2, 3, cbFunction)

I'm invoking the cbFunction inside the caller function. Could you help me to understand why it isn't adding x, y, z? I'm learning JS as a beginner and thank you for your help!

Why do you think it doesn't add the numbers? You're not doing anything with the result other than returning it and caller doesn't care about the return value either. — Andreas
– Andreas, Commented Jul 10, 2021 at 21:21
It actually is adding x, y and z, however you're not doing anything with the result of cbFunction, you could try return cbFunction(x, y, z) in the caller functionthen console.log(caller(1, 2, 3, cbFunction)); — Ameer
– Ameer, Commented Jul 10, 2021 at 21:22

Spectric · Accepted Answer · 2021-07-10 21:26:30Z

1

It is adding the numbers - you just aren't doing anything with the result returned by cbFunction.

Instead, return the result returned by cbFunction:

function cbFunction(x, y, z) {
  return x + y + z
}

function caller(x, y, z, cbFunction) {
  console.log('In caller function!')
  // your code here
  if (typeof cbFunction === "function") {
    return cbFunction(x, y, z); //<-- return
  }
}

console.log(caller(1, 2, 3, cbFunction))

answered Jul 10, 2021 at 21:26

Spectric

32.6k6 gold badges32 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Monde Over a year ago

I see it now. Thank you so much for the explanation!

Monde Over a year ago

Yeah, i tried but it asked me wait for a couple mins. I will.

Collectives™ on Stack Overflow

Trying to understand Callback function

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related