findElement by cssSelector in Selenium Java - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does findElement(By.cssSelector()) do in Selenium?

It locates the first web element on the page that matches the given CSS selector string.

beginner

Write a CSS selector to find an element with class btn-primary.

Use <code>".btn-primary"</code> as the CSS selector. The dot <code>.</code> means class in CSS selectors.

beginner

How do you find an element with id login using CSS selector?

Use "#login" as the CSS selector. The hash # means id in CSS selectors.

intermediate

What is the difference between findElement and findElements?

findElement returns the first matching element or throws an exception if none found. findElements returns a list of all matching elements or an empty list if none found.

intermediate

Why is using CSS selectors often preferred over XPath in Selenium?

CSS selectors are usually faster and simpler to write. They are well supported by browsers and easier to read for many common cases.

Which CSS selector finds all elements with class 'active'?

A "#active"

B "active"

C ".active"

D "*active"

The dot (.) before 'active' selects elements by class name.

What does the CSS selector '#submitBtn' select?

A Elements with id 'submitBtn'

B Elements with name 'submitBtn'

C All buttons

D Elements with class 'submitBtn'

The hash (#) selects elements by their id attribute.

What happens if findElement(By.cssSelector()) finds no matching element?

A Throws NoSuchElementException

B Returns an empty list

C Returns null

D Returns a default element

findElement throws NoSuchElementException if no element matches.

Which CSS selector finds all input elements inside a form?

A "form > input"

B "form input"

C "input form"

D "form + input"

"form input" selects all input elements inside any form, at any depth.

Which is a valid CSS selector to find a button with both classes 'btn' and 'primary'?

A ".btn#primary"

B "#btn.primary"

C "btn.primary"

D ".btn.primary"

Multiple classes are chained with dots: .btn.primary means element with both classes.

Explain how to use findElement(By.cssSelector()) to locate a web element by class and id.

Think about how CSS selectors identify elements by id and class.

Describe the difference between findElement and findElements when using CSS selectors in Selenium.

Consider what happens if no elements match.