Front End Development Front-End Development 2

Question 1

Which CSS property creates a new stacking context for an element?

Accepted Answer

position: relative with z-index

Answer

Setting position to relative, absolute, fixed, or sticky combined with a z-index value other than auto creates a new stacking context.

Question 2

In JavaScript, what does the spread operator (...) do when used with an array?

Accepted Answer

Expands the array into individual elements

Answer

The spread operator expands an iterable like an array into individual elements, useful for copying or merging arrays.

Question 3

What is the purpose of the CSS `will-change` property?

Accepted Answer

Hints to the browser which properties will animate for optimization

Answer

The `will-change` property informs the browser ahead of time which properties will change, allowing it to set up optimizations like compositing layers.

Question 4

Which HTTP status code indicates a resource has been permanently moved?

Accepted Answer

301

Answer

301 Moved Permanently tells the client and search engines that the resource has permanently moved to a new URL.

Question 5

In React, when does `useEffect` with an empty dependency array run?

Accepted Answer

Only once after the initial render

Answer

An empty dependency array `[]` causes useEffect to run only once after the component's initial mount, similar to componentDidMount.

Front End Development Practice Test

Front End Development Practice Test

Front End Development Front-End Development 2