Question

What does document.querySelector(".class") do?

• A. Throws an error if multiple elements have the same class
• B. Selects all elements with the given class name
• C. Selects the first element with the given class name
• D. Selects an element only if it has an ID

Hint:

The plain querySelector returns one node; which one when many match?

Answer 1

The Correct Option is C

Step 1: document.querySelector() takes a CSS selector and returns a single element.

Step 2: The selector ".class" matches elements by class name. When several elements share the class, querySelector returns only the first match in document order.

Step 3: To get every match you would use querySelectorAll(), which returns a NodeList. querySelector never throws for multiple matches and does not require an ID.

Step 4: So it selects the first element with the given class name.