[State] setState #reactn

r

First, whenever you're updating the state based off the previous state (like count in your example), you'll want to use functional setState.

this.setState((currentState) => ({
  count: currentState.count + 1
}))

If you don't, you'll most likely run into some issues. https://medium.com/@shopsifter/using-a-function-in-setstate-instead-of-an-object-1f5cfd6e55d1

Second, I don't love that pattern. Can't you just calculate if it's even before you setState?

this.setState((currentState) => {
  const newCount = currentState.count + 1;
  const countType = newCount % 2 === 0 ? 'even' : 'odd'

  return {
    count: newCount,
    countType,
  }
})