JS DOM Manipulation - styling elements || JavaScript Series 2024

Summary

This tutorial covers how to manipulate class names using JavaScript's `classList` property. It explains how to retrieve, add, remove, toggle, and check for classes on HTML elements, offering a practical guide on dynamic CSS management. The session also touches on inline styling, setting CSS properties, and the ability to interact with multiple class names effectively. The instructor emphasizes hands-on learning, promising further exploration into browser events, asynchronous functions, and more advanced topics in upcoming lessons.

Takeaways

• 😀 JavaScript's `classList` property allows you to easily manage multiple classes on HTML elements.
• 😀 You can retrieve the classes applied to an element using `classList` as an array-like object.
• 😀 The `classList.add()` method helps you add one or more classes to an element.
• 😀 Use `classList.remove()` to remove specific classes from an element.
• 😀 `classList.toggle()` is used to add a class if it's missing or remove it if it's present, useful for alternating states.
• 😀 The `classList.contains()` method checks whether a specific class exists on an element.
• 😀 JavaScript allows dynamic changes to the styles of HTML elements via inline styles or by adding/removing classes.
• 😀 You can modify the style of elements directly using JavaScript’s `style` property or manipulate CSS properties through `setAttribute()`.
• 😀 Adding and removing multiple classes or manipulating the class list allows for flexible styling changes without altering HTML directly.
• 😀 Understanding JavaScript's DOM manipulation with classes is essential for interactive web design and responsive UI development.
• 😀 The lesson also emphasizes upcoming advanced topics like browser events, promises, and asynchronous programming in future sessions.

Q & A

What is the purpose of the `classList` property in JavaScript?

The `classList` property provides a convenient way to manipulate the classes of an HTML element. It allows you to add, remove, toggle, and check for the presence of classes dynamically.

How can you add a new class to an element using `classList`?

You can add a new class using the `classList.add()` method. For example, `element.classList.add('new-class')` will add the `new-class` to the element.

What does the `classList.remove()` method do?

The `classList.remove()` method is used to remove a specified class from an element. For example, `element.classList.remove('old-class')` will remove the `old-class` from the element.

What is the difference between `classList.add()` and `classList.toggle()`?

The `classList.add()` method adds a class to an element if it's not already present, while `classList.toggle()` either adds the class if it is not present or removes it if it is present. `toggle()` is useful for switching between two states.

What happens when you use the `classList.toggle()` method on an element's class?

The `classList.toggle()` method checks if a class is present on an element. If it is, the class is removed; if it is not, the class is added. This makes it useful for toggling between two different styles or states.

How can you check if a class is present on an element using `classList`?

You can check if a class is present using the `classList.contains()` method. It returns `true` if the class is present and `false` if it is not. For example, `element.classList.contains('target-class')` will check for the presence of `target-class`.

What is the output of `classList.contains()` when the class is present and when it is not?

If the class is present on the element, `classList.contains()` returns `true`. If the class is absent, it returns `false`.

Can you manipulate inline styles with JavaScript in the same way as class properties?

Yes, inline styles can be manipulated using JavaScript by directly setting the `style` property of an element. For instance, `element.style.color = 'red'` will change the text color of the element to red.

What is the advantage of using `classList` over traditional methods for manipulating classes?

The advantage of `classList` is that it provides a simple and efficient way to manage multiple classes. It avoids the need to manually parse or manipulate the `class` attribute, making the code cleaner and easier to work with.

What upcoming topics are mentioned at the end of the script for future lessons?

The speaker mentions that future topics will include browser events, the `await` function, and promises in JavaScript, which are essential for handling asynchronous operations and user interactions.