Search⌘ K
Home
Courses
Learn React Hooks for Frontend Development

Understanding the useMemo Design

Explore the design and workflow of React's useMemo hook to manage memoized values efficiently. Understand how useMemo reduces costly recalculations by caching previous results based on dependency changes, enhancing application performance.

We'll cover the following...

Introduction to the useMemo hook

React adds a useMemo hook that allows us to reuse the previous assignment in an update.

React provides a useMemo hook to support a value assignment through a function that can either return a new value or an old value from the previous update:

const Title = () => {
  const label = useMemo(() => {
    return "Hello World"
  }, [])
}
Using useMemo to memoize the constant label "Hello World"

The useMemo workflow summary

Let's understand this from a higher level, the following diagram outlines the useMemo hook in terms of the effects workflow in React (see the image below):

useMemo workflow
useMemo workflow

Compared to useState and useEffect, useMemo is quite straightforward. ...