Front End Development Front-End Development 5

Question 1

What is the purpose of a CSS custom property (variable), declared with `--`?

Accepted Answer

To store reusable values that can be referenced throughout a stylesheet

Answer

CSS custom properties (variables) like `--primary-color: blue;` store values that can be reused with `var(--primary-color)`, making stylesheets more maintainable.

Question 2

Which technique allows a webpage to load JavaScript only when it's needed, reducing initial load time?

Accepted Answer

Code splitting and lazy loading

Answer

Code splitting breaks a bundle into smaller chunks that can be lazy loaded on demand (e.g., when a user navigates to a specific route), reducing the initial JavaScript payload.

Question 3

In the browser's rendering pipeline, what happens during the 'paint' phase?

Accepted Answer

The browser fills in pixels — colors, borders, shadows, and text

Answer

During the paint phase, the browser rasterizes each layer by filling in the actual pixel values for visual properties like colors, backgrounds, borders, and shadows.

Question 4

What does the `srcset` attribute on an `<img>` element allow you to do?

Accepted Answer

Provide different image sources for different screen resolutions or sizes

Answer

The srcset attribute lets you specify multiple image sources at different resolutions or widths so the browser can choose the most appropriate one for the device.

Question 5

What is the purpose of `aria-label` in HTML?

Accepted Answer

It provides an accessible name for an element for screen readers when no visible text is available

Answer

aria-label provides a text alternative that screen readers announce for elements that lack visible descriptive text, improving accessibility.

Front End Development Practice Test

Front End Development Practice Test

Front End Development Front-End Development 5