Virtual DOM - Optimizing with shouldComponentUpdate

Show how to implement shouldComponentUpdate lifecycle method to avoid unnecessary Virtual DOM diff calculations and renders.

class MyComponent extends React.Component {

  shouldComponentUpdate(nextProps, nextState) {
    // Perform a shallow comparison to determine if props or state have changed
    // Returning false if they haven't changed will avoid re-rendering
    return this.props.value !== nextProps.value || this.state.count !== nextState.count;
  }

  render() {
    // Component render function
    return (
      <div>{this.props.value} - {this.state.count}</div>
    );
  }

}

The shouldComponentUpdate lifecycle method is used here to compare the current props and state to the next props and state. It returns true to continue with the render or false to cancel the render if there are no changes, thus optimizing performance by avoiding unnecessary renders.