Understand JavaScript Events with Examples

• Event Handler in JavaScript
• Common Event Listeners
• The addEventListener() method
• HTML event handlers attributes
• Frequently Asked Questions

Event Handler in JavaScript

JavaScript provides several built-in functions for creating custom events. These functions are useful when you need to trigger an event in response to something happening on the page. For example, you might use a function to display a message after someone clicks a button or maybe Javascript array examples.

Common Event Listeners

A JavaScript event object contains data about the event that occurred. It's similar to how an HTML form element stores its data. You can access the properties of the event object using the event object's name as a string. For example, the following code creates new events named "click" with two properties: the type (which is "click") and the value ("button1"). Here is a complete list of HTML DOM Event Objects.

In a minute we'll look at a variety of different events examples. The key thing to note is that anyone of the previously mentioned DOM Event objects can be used with any HTML element, e.g.

Onclick Event Handler Example

Let's start with the most common Javascript event handler, the onclick event which is called when a user clicks, in this example, a button.

<button onclick="alert('Onclick Events')">On Click</button>

Onfocus Event Handler Example

The onfocus events is called when the element is focused on by the user.

<button onfocus="alert('Onfocus Events')">On Focus</button>

Onmouseout Event Handler Example

The onmouseout event handler is executed when the user's mouse was over an element and then moves its focus off of it.

<button onmouseout="alert('Onmouseout Events')">On Mouseout</button>

Onmouseover Event Handler Example

The onmouseover events is called when the user's mouse button is hovering over the element.

<button onmouseover="alert('Onmouseover Events')">On Mouseover</button>

Onkeyup Event Handler Example

The onkeyup event handler occurs when a key is pressed on the element with the events on it.

<button onkeyup="alert('Onkeyup Events')">On Keyup</button>

Onload Event Handler Example

When the browser finishes loading the document an event handler is trigged called onload. This event is very commonly used to execute Javascript events as soon the document finishes loading on the browser.

<button onload="alert('Onload Events')">On Load</button>

Onchange Event Handler Example

When the value of the element changes, the event called onchange is executed which is an event handler that is very commonly with the following example.

<button onchange="alert('Onchange Events')">On Change</button>

The addEventListener() method

The browser creates a loop called the "event loop" that runs continuously while the user interacts with the web page. This loop handles all input events (such as mouse clicks) and output events (such as when the screen refreshes). It does not handle any other type of events, such as those generated by JavaScript code.

To use a custom event, you need to define an object that will receive the event. You then register the event handler function using addEventListener().

HTML event handlers attributes

An event handler is a function that runs when an event occurs. This function receives the event object as a parameter. The event object contains data about what happened. For example, the event object might contain the type of event (such as click) and the location where the event occurred (such as button1).

JavaScript provides several ways to create custom events. You can use the addEventListener() method to attach a listener to an element. You can also use the dispatchEvent() method to send an event to another element. Finally, you can use the triggerEvent() method to simulate an event. Let's take a closer look at each of these methods.

Frequently Asked Questions

What is an event on a website in JS?

An event is an action that is triggered when the user clicks or uses the mouse pointer to trigger an event handler.

What are the 8 types of JavaScript events?

As mentioned above, there are more than just 8 Javascript events, but the most common ones are:

1. onclick
2. onchange
3. onload
4. onkeyup
5. onmouseover
6. onmouseout
7. onkeydown
8. onhover

How do you write an event in JavaScript?

To write an event in Javscript you create an HTML element and then apply the event type to that element, e.g. the button.

What is the event object JS?

The event object is an input type on the function that gets executed when the browser triggers an event handler.

What do you mean by JavaScript events?

JavaScript allows you to execute your code when events are detected by the browser.

What is JavaScript event handling?

When the user presses the button or when the mouse hovers over an object is an example of event handling with Javascript.

What are events in JavaScript and its types?

When the button is pressed, Javascript triggers events. These types can be anything from change events to click event and many other types for an event handler.

What is event and function?

An event handler is the function that gets executed, for example, when the button is pressed or when the mouse moves over an object.

What are events and event handlers in JavaScript?

The term events and event handlers are interchangeable terms and are called when the mouse or the button interact with an element on the page.

What are event objects in JavaScript?

Event objects is the HTML element that the user clicks or is interacting with on the document or the browser.

What is an event on a website JavaScript?

HTML events are actions that happen to HTML elements in the document.

What is event handling in JavaScript with example?

Up above I provided 8 different examples of Javascript events, hopefully these will get you started.

What is meant by event handling?

Event handling happens, for example, when the mouse is pressed or the button is clicked.

What are the types of JavaScript event handler?

There is a very long list of HTML DOM event handlers.

What is event handling explain types of event with example?

Event handlers are actions you can execute when the button is pressed or the mouse is clicked.

What are the event handlers in JavaScript?

There are many different event handlers in Javascript, the most common are: onclick, onchange, onload, etc.

What is event Handler?

An event handler is when a function is executed by an action the user clicks on the webpage.

What are the event handlers explain the JavaScript event handlers with examples?

You can use Javascript events handlers to perform an event when the user performs almost any action on the browser.

Published on Jul 28, 2022

Tags: AJAX | events | JavaScript