JavaScript events and event handling

JavaScript events are actions or occurrences that happen in the browser, such as a user clicking a button, typing in a text field, or loading a web page. Event handling in JavaScript involves writing code to respond to these events and perform certain actions in response.

Here’s an overview of JavaScript events and event handling:

Event Types

JavaScript supports a wide variety of events, including:

• Click events
• Key events (e.g. keydown, keyup, keypress)
• Mouse events (e.g. mousedown, mouseup, mousemove)
• Form events (e.g. submit, reset)
• Window events (e.g. load, unload, resize)

• Event Listeners

To handle events in JavaScript, you can attach event listeners to specific elements in the DOM. An event listener is a function that is executed when an event occurs. You can attach event listeners to an element using the addEventListener() method.

• Event Objects

When an event occurs, an event object is created that contains information about the event. This object can be accessed within the event listener function using the event parameter. The event object contains properties that provide information about the event, such as the target element, the type of event, and the position of the mouse pointer.

• Event Propagation

JavaScript events propagate through the DOM, which means that an event that occurs on a child element will also trigger any event listeners on its parent elements. Event propagation can be controlled using the stopPropagation() method to prevent the event from bubbling up to parent elements.