Start Coding with jQuery: Vol. 1 - Adding JavaScript to Your HTML
jQuery for Total Noobs Vol. 1: Adding JavaScript
Have you ever wanted to make your web pages more dynamic and interactive? Have you ever wondered how to use JavaScript to manipulate the HTML elements on your page? Have you ever felt overwhelmed by the complexity and verbosity of JavaScript code? If you answered yes to any of these questions, then this article is for you!
jQuery for Total Noobs Vol. 1: 6 Adding JavaScript
In this article, you will learn about jQuery, which is a JavaScript library that simplifies web development. You will learn how to include jQuery in your web page, how to use jQuery selectors and methods, how to handle events with jQuery, how to manipulate the DOM with jQuery, and how to use jQuery effects and animations. By the end of this article, you will be able to add some interactivity and flair to your web pages using jQuery.
What You Need to Know Before Learning jQuery
Before you start learning jQuery, you should have a basic knowledge of HTML, CSS, and JavaScript. HTML is the markup language that defines the structure of your web page. CSS is the style sheet language that defines the appearance of your web page. JavaScript is the programming language that defines the behavior of your web page.
If you want to refresh your knowledge of these topics, you can find some tutorials on our Home page. You don't need to be an expert in these topics, but you should be familiar with the basic syntax and concepts.
How to Include jQuery in Your Web Page
There are several ways to include jQuery in your web page. The easiest way is to use a CDN (Content Delivery Network), which is a server that hosts the jQuery file and delivers it to your browser when requested. To use a CDN, you just need to add a tag in your HTML file that links to the CDN URL.
For example, you can use the Google CDN to include the latest version of jQuery in your web page:
You can also use other CDNs, such as jQuery's own CDN or cdnjs. The advantage of using a CDN is that you don't need to download and store the jQuery file on your own server, and you can benefit from the CDN's speed and reliability.
Another way to include jQuery in your web page is to download the jQuery file from jQuery's website and save it in your local folder. Then, you can add a tag in your HTML file that links to the local file.
For example, if you save the jQuery file as jquery-3.6.0.min.js in the same folder as your HTML file, you can include it like this:
The advantage of using a local file is that you don't need to rely on an external server, and you can use jQuery offline. However, you need to make sure that you have the latest version of jQuery, and that you update it regularly.
A third way to include jQuery in your web page is to use an online editor, such as W3Schools' Try it Yourself or CodePen. These editors allow you to write and run HTML, CSS, and JavaScript code in your browser, without the need to set up a local server or download any files. They also provide some options to include jQuery and other libraries in your code.
The advantage of using an online editor is that you can easily experiment with jQuery and see the results instantly. However, you need to have an internet connection, and you may not be able to save or share your code easily.
How to Use jQuery Selectors and Methods
The basic syntax of jQuery is:
$(selector).method()
This means that you use the $ sign to access jQuery, then you use a selector to find one or more HTML elements, and then you apply a method to them.
Common jQuery Selectors
A selector is a string that specifies which HTML elements you want to select. You can use any CSS selector as a jQuery selector, as well as some additional selectors that are specific to jQuery.
Here are some examples of common jQuery selectors:
Selector Example Description --- --- --- * $("*") Selects all elements tagname $("p") Selects all elements #id $("#intro") Selects the element with id="intro" .class $(".red") Selects all elements with [attribute] $("[href]") Selects all elements with an href attribute [attribute=value] $("[href='https://www.w3schools.com']") Selects all elements with href="https://www.w3schools.com" :first $("p:first") Selects the first element :last $("p:last") Selects the last element :even $("tr:even") Selects all even elements :odd $("tr:odd") Selects all odd elements You can also combine multiple selectors using commas or spaces, to select more specific elements.
For example:
Selector Example Description --- --- --- Common jQuery Methods
A method is a function that performs some action on the selected elements. jQuery has many methods that can be used to manipulate the content, style, and behavior of the HTML elements.
Here are some examples of common jQuery methods:
Method Example Description --- --- --- hide() $("p").hide() Hides all elements show() $("p").show() Shows all elements toggle() $("p").toggle() Toggles between hiding and showing all elements html() $("p").html("Hello") Sets the HTML content of all elements to "Hello" text() $("p").text("Hello") Sets the text content of all elements to "Hello" val() $("input").val("John") Sets the value of all elements to "John" attr() $("a").attr("href", "https://www.w3schools.com") Sets the href attribute of all elements to "https://www.w3schools.com" removeAttr() $("a").removeAttr("href") Removes the href attribute of all elements You can also chain multiple methods together, using a dot (.) to separate them.
For example:
$("p").hide().html("Hello").show()
This will hide all elements, change their HTML content to "Hello", and then show them again.
How to Handle Events with jQuery
An event is something that happens on your web page, such as a click, a hover, a keypress, a load, etc. You can use jQuery to execute some code when an event occurs on a selected element.
The basic syntax of jQuery event handling is:
$(selector).event(function)
This means that you use the same selector as before to find one or more HTML elements, then you specify an event that you want to listen for, and then you provide a function that will run when the event occurs.
Common jQuery Events
jQuery supports many types of events, such as mouse events, keyboard events, form events, document events, window events, etc.
Here are some examples of common jQuery events:
Event Example Description --- --- --- click() $("button").click(function) Executes a function when a button is clicked hover() $("div").hover(function1, function2) Executes function1 when the mouse enters a div element, and function2 when the mouse leaves it keypress()$("input").keypress(function) Executes a function when a key is pressed on an input element load() $(window).load(function) Executes a function when the window is fully loaded ready() $(document).ready(function) Executes a function when the document is ready to be manipulated resize() $(window).resize(function) Executes a function when the window is resized You can also use the on() method to attach one or more event handlers to one or more elements.
For example:
$("p").on("click", function)
This will execute a function when any element is clicked.
How to Use the ready() Method
A common mistake that beginners make is to try to run jQuery code before the document is fully loaded. This can cause errors, because jQuery may not be able to find the elements that you want to manipulate.
To avoid this problem, you should always use the ready() method, which ensures that your jQuery code runs only after the document is ready. The ready() method takes a function as an argument, and executes it when the document is ready.
The syntax of the ready() method is:
$(document).ready(function)
or
$().ready(function)
or
$(function)
All these syntaxes are equivalent, but the last one is the shortest and most commonly used.
For example:
$(function() // Your jQuery code goes here );
This will run your jQuery code when the document is ready.
How to Manipulate the DOM with jQuery
The DOM (Document Object Model) is a tree-like representation of your web page, where each node is an object that corresponds to an HTML element. You can use jQuery to manipulate the DOM, which means that you can change the content and style of the HTML elements on your page.
How to Add and Remove Elements with jQuery
You can use jQuery to add new elements to the DOM, or remove existing elements from the DOM. There are several methods that you can use for this purpose, depending on where you want to insert or delete the elements.
The following table summarizes some of these methods:
Method Description --- --- append() Inserts content at the end of the selected elements append() Inserts content at the end of the selected elements prepend() Inserts content at the beginning of the selected elements after() Inserts content after the selected elements before() Inserts content before the selected elements remove() Removes the selected elements and their child elements empty() Removes the child elements of the selected elements The content that you want to insert or remove can be a string of HTML, a jQuery object, or a DOM element.
For example:
// Append a new paragraph to the end of the div element $("div").append("This is a new paragraph"); // Prepend a new heading to the beginning of the div element $("div").prepend("This is a new heading
"); // Insert a new list item after the second list item $("li:eq(1)").after("This is a new list item
"); // Insert a new list item before the first list item $("li:first").before("This is a new list item
"); // Remove all paragraphs from the document $("p").remove(); // Empty all div elements $("div").empty();
How to Add and Remove Classes with jQuery
You can use jQuery to add or remove classes from the selected elements. Classes are useful for applying CSS styles or identifying elements for further manipulation.
The following methods can be used to add or remove classes:
Method Description --- --- addClass() Adds one or more classes to the selected elements removeClass()toggleClass()The classes that you want to add or remove can be specified as a string of space-separated names, or as a function that returns a string.
For example:
// Add the red class to all paragraphs $("p").addClass("red"); // Remove the red class from all paragraphs $("p").removeClass("red"); // Toggle between adding and removing the red and blue classes from all paragraphs $("p").toggleClass("red blue");
How to Change CSS Properties with jQuery
You can use jQuery to change the CSS properties of the selected elements. CSS properties are used to define the appearance and layout of your web page.
The following methods can be used to change CSS properties:
Method Description --- --- css()css()animate()The CSS properties that you want to set or return can be specified as a string of a single property name, or as an object of multiple property-value pairs. The values can be numbers, strings, or functions that return a value.
For example:
// Set the background color of all paragraphs to yellow $("p").css("background-color", "yellow"); // Return the font size of the first paragraph $("p:first").css("font-size"); // Set the width and height of all div elements to 100px $("div").css( width: 100, height: 100 ); // Animate the width and height of all div elements to 200px in 2 seconds $("div").animate( width: 200, height: 200 , 2000);
How to Use jQuery Effects and Animations
You can use jQuery to create dynamic and interactive web pages by applying effects and animations to the selected elements. Effects and animations are used to show, hide, or move elements in a smooth and elegant way.
The following methods can be used to apply effects and animations:
Method Description --- --- show()hide()toggle()fadeIn()fadeOut()fadeToggle()fadeTo()slideUp()slideDown()slideToggle()All these methods take an optional parameter that specifies the duration of the effect or animation, in milliseconds or as a string ("slow" or "fast"). They also take an optional callback function that runs after the effect or animation is completed.
For example:
// Show all paragraphs with a slow speed $("p").show("slow"); // Hide all paragraphs with a fast speed and alert a message when done $("p").hide("fast", function() alert("All paragraphs are hidden"); ); // Toggle between fading in and out all div elements with a default speed $("div").fadeToggle(); // Fade all div elements to 50% opacity in 2 seconds $("div").fadeTo(2000, 0.5); // Slide up all list items with a default speed and alert a message when done $("li").slideUp(function() alert("All list items are slid up"); ); // Slide down all list items with a slow speed $("li").slideDown("slow");
Conclusion and Next Steps
In this article, you learned about jQuery, which is a JavaScript library that simplifies web development. You learned how to include jQuery in your web page, how to use jQuery selectors and methods, how to handle events with jQuery, how to manipulate the DOM with jQuery, and how to use jQuery effects and animations.
By now, you should be able to add some interactivity and flair to your web pages using jQuery. However, this is only the beginning of your jQuery journey. There are many more features and functionalities that jQuery offers, such as AJAX, plugins, widgets, etc. You can explore them in our next articles on jQuery for total noobs.
If you want to learn more about jQuery, you can visit the following resources:
W3Schools jQuery Tutorial: A comprehensive tutorial that covers all aspects of jQuery.
jQuery Learning Center: A collection of articles and guides that explain various topics on jQuery.
jQuery API Documentation: A reference of all jQuery selectors, methods, properties, and events.
We hope you enjoyed this article and learned something new. Happy coding!
FAQs
Here are some frequently asked questions about jQuery:
What is the difference between jQuery and JavaScript?
jQuery is a JavaScript library, which means that it is a collection of pre-written JavaScript code that you can use in your web page. JavaScript is the programming language that jQuery is written in, and that you can use to write your own code.
How do I know if jQuery is working on my web page?
One way to check if jQuery is working on your web page is to open the browser's console (usually by pressing F12 or Ctrl+Shift+I) and type $ in the console. If you see a function definition, then jQuery is working. If you see an error message, then jQuery is not working.
How do I update jQuery to the latest version?
If you are using a CDN to include jQuery in your web page, then you can update jQuery by changing the URL of the tag to point to the latest version. For example, if you are using the Google CDN, you can change the URL from https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js to https://ajax.googleapis.com/ajax/libs/jquery/4.0.0/jquery.min.js. If you are using a local file to include jQuery in your web page, then you can update jQuery by downloading the latest version from jQuery's website and replacing the old file with the new one.
How do I use jQuery with other JavaScript libraries?
jQuery can work well with other JavaScript libraries, such as Bootstrap, Angular, React, etc. However, sometimes there may be conflicts between jQuery and other libraries that use the same $ sign as a shortcut. To avoid these conflicts, you can use the noConflict() method, which releases the control of the $ sign to other libraries. For example, you can write var jq = $.noConflict(), and then use jq instead of $ to access jQuery.
How do I debug jQuery code?
You can debug jQuery code using the same tools and techniques that you use to debug JavaScript code, such as the browser's console, debugger, breakpoints, etc. You can also use some jQuery-specific methods, such as .