Articles Tagged reduce

useReducer is one of a handful of React hooks that shipped in React 16.7.0. It accepts a reducer function with the application initial state, returns the current application state, then dispatches a function.

Here is an example of how it is used;

const [state, dispatch] = useReducer(reducer, initialState);

Writing asynchronous JavaScript without using the Promise object is a lot like baking a cake with your eyes closed. It can be done, but it’s gonna be messy and you’ll probably end up burning yourself.

I won’t say it’s necessary, but you get the idea. It’s real nice. Sometimes, though, it needs a little help to solve some unique challenges, like when you’re trying to sequentially resolve a bunch of promises in order, one after the other. A trick … Read article “Why Using reduce() to Sequentially Resolve Promises Works”

I was recently mentoring someone who had trouble with the .reduce() method in JavaScript. Namely, how you get from this:

const nums = [1, 2, 3]
let value = 0

for (let i = 0; i < nums.length; i++) {
  value += nums[i]
}

…to this:

const nums = [1, 2, 3]
const value = nums.reduce((ac, next) => ac + next, 0)

They are functionally equivalent and they both sum up all the numbers in the array, but there is … Read article “Understanding the Almighty Reducer”