CODEWITHSUNDEEP
javascript
Dawn17
Dawn17

Reputation: 8297

Getting the first item with a condition in an array returned asynchronously in JavaScript

I have a function called getItems that returns an array of objects asynchronously. Each object has a isOccupied method that returns a boolean.

I wrote a function that takes an index and returns whether index-th item in the array's isOccupied is true or false.

I wrote a function to return the index of the item from the array returned by getItems.

    async getOccupiedItemIndex() {
      let selectedIdx = 0;
      return getItems().then(items => {
        items.forEach((item, index) => {
          if (item.isOccupied()) selectedIdx = index;
        });
        return selectedIndex;
      });
    }

I want to improve this function because

  1. The fact that we are using an async function to use an array makes it lengthy.

  2. I see that if there is no item found, it could return null?

  3. We can assume that there will only be one occupied item in the array.

Any thoughts on improving this?

Upvotes: 1

Views: 139

Answers (3)

Youssouf Oumar
Youssouf Oumar

Reputation: 46121

Since you are in an async function, awaiting getIems will simplify your logic, like so:

async function getOccupiedItemIndex() {
  const items = await getItems();
  let selectedIdx = null;

  for (let i = 0; i < items.length; i++) {
    if (items[i].occupied()) {
      selectedIdx = i;
      break;
    }
  }

  return selectedIdx;
}

Upvotes: 0

Jupri
Jupri

Reputation: 365

You could use Array.findIndex() :

const getOccupiedItemIndex = () => 
      getItems().then( items => items.findIndex( item => item.isOccupied() ) )

will find first occupied index or -1 if not found

Upvotes: 2

Friksel
Friksel

Reputation: 140

You could return the right variable. selectedIndex isn't declared. Only selectedIdx is.

Upvotes: 0

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