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What is JavaScript?
JavaScript is a versatile programming language that is primarily used to create and control dynamic website content. Anything that moves, changes, updates, or reacts on a web page without requiring a page reload is likely powered by JavaScript.
Basic JavaScript Syntax
Here’s a simple example of JavaScript that changes the content of an HTML element:
<!DOCTYPE html>
<html>
<head>
<title>JavaScript Example</title>
<script>
function changeText() {
document.getElementById("myText").innerHTML = "Hello, JavaScript!";
}
</script>
</head>
<body>
<p id="myText">Click the button to change this text.</p>
<button onclick="changeText()">Click me</button>
</body>
</html>
<script>: Defines a client-side script (JavaScript).document.getElementById: Selects an HTML element by its ID..innerHTML: Sets or returns the HTML content of an element.onclick: An event that occurs when an element is clicked.
What is jQuery?
jQuery is a fast, small, and feature-rich JavaScript library. It simplifies things like HTML document traversal and manipulation, event handling, and animation, making it much easier to use JavaScript on your website.
Including jQuery in Your Project
To use jQuery, you need to include it in your HTML file. You can do this by linking to a CDN (Content Delivery Network):
<!DOCTYPE html>
<html>
<head>
<title>jQuery Example</title>
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
</head>
<body>
<p id="myText">Click the button to change this text.</p>
<button id="myButton">Click me</button>
<script>
$(document).ready(function() {
$("#myButton").click(function() {
$("#myText").text("Hello, jQuery!");
});
});
</script>
</body>
</html>
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>: Includes the jQuery library.$(document).ready: Ensures the script runs only after the document is fully loaded.$("#myButton").click: Attaches a click event handler to the button.$("#myText").text: Changes the text content of the selected element.
jQuery Selectors
jQuery selectors are used to “find” (or select) HTML elements based on their id, class, type, attributes, values of attributes, and much more.
Examples of jQuery Selectors
<!DOCTYPE html>
<html>
<head>
<title>jQuery Selectors</title>
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script>
$(document).ready(function() {
// Select element by ID
$("#myText").css("color", "blue");
// Select elements by class
$(".myClass").css("font-size", "20px");
// Select elements by element type
$("p").css("background-color", "yellow");
});
</script>
</head>
<body>
<p id="myText">This is a paragraph with an ID.</p>
<p class="myClass">This is a paragraph with a class.</p>
<p>This is a regular paragraph.</p>
</body>
</html>
–
$("#myText").css("color", "blue");: Changes the text color of the element with the IDmyTextto blue.$(".myClass").css("font-size", "20px");: Changes the font size of all elements with the classmyClassto 20px.$("p").css("background-color", "yellow");: Changes the background color of all<p>elements to yellow.
Conclusion
JavaScript and jQuery are powerful tools for web development. JavaScript allows you to create dynamic and interactive web pages, while jQuery simplifies many of the common tasks involved in manipulating the DOM and handling events. By mastering these technologies, you can greatly enhance the user experience on your websites.
