Solved: onkeydown react

First of all, let’s talk about componentDidCatch, which is a very significant lifecycle method in React. This method works as a JavaScript error boundary. If an error is thrown in a component, componentDidCatch method catches the error and displays a fallback UI instead of crashing the whole app. It’s a part of “Error Boundaries” concept in React 16 and higher.

There are different ways to use this lifecycle method. However, handling keydown events in React components is a common requirement, and one of the strategies applied is to implement an onKeyDown event. Let’s dive right into the solution.

class (YourComponent) extends React.Component {
  onKeyDown(event) {
    switch (event.keyCode) {
      case 27:
        // logic here

  componentWillMount() {
    document.addEventListener('keydown', this.onKeyDown.bind(this));

  componentWillUnmount() {
    document.removeEventListener('keydown', this.onKeyDown.bind(this));

Now, let’s go through a step-by-step explanation of the code.

Event handling in React

React provides synthetic events which are wrappers around browser’s native events to ensure events have consistent properties across different browsers. The ‘onKeyDown’ function is an event handler that is called when a user presses a key.

Component Lifecycle Methods

When a component is rendered to a DOM, it goes through several lifecycle stages – Mounting, Updating and Unmounting. It gives the ability to encapsulate React components of certain aspects of their behavior. We’re adding an event listener in componentWillMount and removing it in componentWillUnmount is to prevent memory leak.

It’s also important to consider other components and libraries involved in handling events in React. Many libraries provide additional features and carry out tasks such as async event handling, or throttle and debounce event handlers.

React has a rich ecosystem of libraries that can ease your development process. For example, ‘react-use’ is a popular library that provides several custom hooks, including ‘useKey’. ‘useKey’ is a hook that can be used to respond to keypress events. This makes it a useful tool in developing interactive React applications.

Also, there are performance-related aspects to consider. For example, in a single page application, if you’re frequently adding and removing event listeners, it may impact on performance. Therefore, it’s important to consider the strategy of adding and removing event listeners.

Handling Keyboard Events

Keyboard events are essential in providing a smooth user experience. React provides ‘onKeyDown’, ‘onKeyPress’, and ‘onKeyUp’ methods to handle these events. Depending on your requirement, you may need to capture just the event of key pressing (‘onKeyDown’ or ‘onKeyPress’), or the event of key release (‘onKeyUp’).

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