setState()

[sidnt]

• enqueues changes to component state
• would all children components be re-rendered with the updated parent state, as well?
• is a request rather than an immediate command to update the component
• react does not guarantee that the requested changes are applied immediately
• doesn't always immediately update the component
• may batch or defer the update for later
• immediately after calling setState(), it's unsound to expect the latest state via this.state
• componentDidUpdate or the setState callback is guaranteed to fire, after the update has been applied
• setState's updater argument can be used to compute new state based on old one

usage guidelines

• This is the primary method you use to update the user interface in response to event handlers and server responses.
• If the next state depends on the current state, we recommend using the updater function form, instead