Why re-rendererd

why-re-rendered.js

componentDidUpdate(prevProps, prevState) {
  Object.entries(this.props || {}).forEach(([key, val]) =>
    prevProps[key] !== val && console.log(`[debug] ${this.constructor.displayName ||
            this.constructor.name} prop '${key}' changed`)
  );
  Object.entries(this.state || {}).forEach(([key, val]) =>
    prevState[key] !== val && console.log(`[debug] ${this.constructor.displayName ||
            this.constructor.name} state '${key}' changed`)
  );
}