Why aren't my function's variables available in my promise's callback?

Asked Jul 19 '18 at 14:21

Active Jul 19 '18 at 14:21

Viewed 24 times

I have the following function. What I'm trying to undestand is, why wouldn't all four variables in the apiCall function be available to the promise resolution via then? Is there a way to access var1, var2 and var3 inside the then callback? Am I misunderstanding Javascript scope or is there something else in my code that could be the culprit?

apiCall (addOrRemove, var1, var2, var3) {
  debugger;  // ALL VARIABLES addOrRemove, var1, var2 and var3 ARE DEFINED HERE
  if (addOrRemove === 'add') {
    let reduxArray = this.state.reduxArray
    reduxArray.push({
      var1: var1,
      var2: var2
    })
    this.setState({
      reduxArray: reduxArray
    })
    this.props.dispatch(actionCreator(var1, var2))
    .then((response) => {
      debugger;  // ONLY var1 IS DEFINED HERE
    })
  }
  ...
}

asked Jul 19 '18 at 14:21

YPCrumble

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Are you saying this based solely on what you see in the debugger? Or have you actually tried `console.log(var2)`? – deceze Jul 19 '18 at 14:24
1

Does this happen in v8? It may be one of its optimizations: https://stackoverflow.com/a/28431346/1651698 – Razem Jul 19 '18 at 14:25
*"Am I misunderstanding Javascript scope"*... probably. And probably misunderstanding debugger context also – charlietfl Jul 19 '18 at 14:27
@deceze you are exactly right. Do you know what on earth is going on? – YPCrumble Jul 19 '18 at 14:28
1

Don't rely too much on debuggers is the lesson, I guess. – deceze Jul 19 '18 at 14:29
@YPCrumble Have you checked the link I posted? It might be really just an optimization. If you used the variable near the debugger statement it would work as you expected. – Razem Jul 19 '18 at 14:31
@Razem that's exactly the problem - thank you. – YPCrumble Jul 19 '18 at 14:37

Why aren't my function's variables available in my promise's callback?

0 Answers0