Question

How to update a component every second?

Answer 1

You need to use setInterval() to trigger the change, but you also need to clear the timer when the component unmounts to prevent errors and memory leaks.

componentDidMount() {
  this.interval = setInterval(() => this.setState({ time: Date.now() }), 1000)
}

componentWillUnmount() {
  clearInterval(this.interval)
}