Events in JavaScript are actions that happen in the browser, such as a user clicking a button, moving the mouse, typing on the keyboard, or loading a page. JavaScript allows you to respond to these events using event handlers.
This blog explains how events work and provides examples of the most common events.
⭐ 1. What Is an Event?
An event is an interaction between the user and the browser. When an event occurs, you can write a function (event handler) to perform a specific task.
⭐ 2. Adding Event Handlers
There are three main ways to handle events:
1. Inline HTML Attribute
<button onclick="alert('Button clicked!')">Click Me</button>
2. Using DOM Property
let btn = document.getElementById("myBtn");
btn.onclick = function() {
alert("Button clicked!");
};
3. Using addEventListener (Recommended)
let btn = document.getElementById("myBtn");
btn.addEventListener("click", function() {
alert("Button clicked!");
});
⭐ 3. Common JavaScript Events
Mouse Events
click→ when an element is clickeddblclick→ double-clickmouseover→ mouse enters elementmouseout→ mouse leaves element
Example:
let box = document.getElementById("box");
box.addEventListener("mouseover", function() {
box.style.backgroundColor = "yellow";
});
Keyboard Events
keydown→ when a key is pressedkeyup→ when a key is releasedkeypress→ when a key is pressed and held
Example:
document.addEventListener("keydown", function(event){
console.log("Key pressed: " + event.key);
});
Form Events
submit→ when a form is submittedfocus→ when an input gains focusblur→ when an input loses focus
Example:
let form = document.getElementById("myForm");
form.addEventListener("submit", function(event){
event.preventDefault(); // prevent form submission
alert("Form submitted!");
});
Window Events
load→ when the page finishes loadingresize→ when the window size changesscroll→ when the user scrolls the page
Example:
window.addEventListener("resize", function() {
console.log("Window resized!");
});
⭐ 4. Event Object
The event object contains information about the event.
document.addEventListener("click", function(event){
console.log("Clicked element:", event.target);
console.log("X coordinate:", event.clientX);
console.log("Y coordinate:", event.clientY);
});
⭐ Conclusion
Events make JavaScript interactive. By using event handlers, you can respond to user actions, update the UI dynamically, and create responsive web applications.
📌 Citations
🔗 View other articles about Javascript:
https://savanka.com/category/learn/js/
🔗 External Javascript Documentation:
https://www.w3schools.com/js/