Assigning callback value to a variable

Question

I'm using the package WordPos which has a function getNouns such that getNouns(text, callback), for example.

wordpos.getNouns('The angry bear chased the frightened little squirrel.', 
console.log)
// [ 'bear', 'squirrel', 'little', 'chased' ]

I want to write the promise to an array rather than logging it and haven't had any luck. Any suggestions?

do you want to use the array in a function or you specifically want to use promises to do this? — Mohit Bhardwaj, Jul 11 '17 at 12:35
What have you tried? Replacing console.log with a function that pushes to an array isn't working? — Liam MacDonald, Jul 11 '17 at 12:35
I want to use that array later on, or add those values to a set. I'm not well versed in promises so I don't know how to go about this. — tittimous, Jul 11 '17 at 13:48

score 1 · Answer 1 · answered Jul 11 '17 at 12:36

1

Why don't you just do

wordpos.getNouns('The angry bear chased the frightened little squirrel.', result => {
  const array = result;
  // do stuff with `array`
})

answered Jul 11 '17 at 12:36

Aron

8,696
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Is there any way to use this array outside of this call? – tittimous Jul 11 '17 at 13:23
Not unless you use Promises or async functions – Aron Jul 11 '17 at 13:23

score 1 · Answer 2 · answered Jul 11 '17 at 12:37

1

You have to wrap this function with a Promise.

function getNounsPromise(string) {
  return new Promise((resolve, reject) => {
    wordpos.getNouns(string, resolve);
  });
} 

// usage:
getNounsPromise('The angry bear chased the frightened little squirrel.')
  .then(result => console.log(result)); // [ 'bear', 'squirrel', 'little', 'chased' ]

answered Jul 11 '17 at 12:37

Michał Pietraszko

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So is it incorrect to do this: var result = getNounsPromise(string).then(result => console.log(result)); if I want to use result as the array? – tittimous Jul 11 '17 at 13:31
1

this is not how asynchronous programming work – Michał Pietraszko Jul 11 '17 at 14:13
You can't serialize a promise. – Michał Pietraszko Jul 11 '17 at 14:13
I figured it out. I read up on promises and async, I do all of the things I need with the variable inside the callback function. Thanks for your help everyone! – tittimous Jul 11 '17 at 14:58

Assigning callback value to a variable

2 Answers2