Modern Web Design with HTML5, CSS3, and JavaScript - Selecting Web Page Elements using JavaScript Element Selectors

The video tutorial covers various methods of selecting HTML elements using JavaScript. It begins with an introduction to the document object and its methods for selecting elements by ID, tag name, and class name. The tutorial explains how selecting by ID returns a single element, while selecting by tag name or class name returns a node list. It also introduces the querySelector and querySelectorAll methods, which offer a more flexible approach to element selection. The tutorial emphasizes the importance of understanding object references and how changes to elements are reflected across different selections.

What is the primary reason for using the document object when selecting elements by ID?

• It allows for selecting multiple elements with the same ID.

• It ensures that the selection is case-sensitive.

• It provides a method to select a unique element on the page.

• It automatically logs the element to the console.

When selecting elements by tag name, what type of collection is returned?

• A string of element names

• An array of elements

• A node list of elements

• A single element

How does JavaScript handle multiple lists referencing the same element object?

• It creates separate copies of the element for each list.

• It updates all references when the element is modified.

• It only updates the first list that references the element.

• It prevents any updates to the element.

What is a key advantage of using querySelector over other selection methods?

• It automatically updates the HTML document.

• It allows for selecting elements by ID, tag, and class in one method.

• It returns all matching elements in an array.

• It can only select elements by ID.

What does querySelector return when multiple elements match the selection criteria?

• The first matching element

• A node list of all elements

• An error message

• All matching elements

Which symbol is used in querySelector to select an element by class?

• .

• *

• #

• &

In the context of querySelector, what does the '#' symbol represent?

• Selecting by class

• Selecting by attribute

• Selecting by tag name

• Selecting by ID