Front End Development Front-End Development Course 5

Question 1

What is the purpose of the `localStorage` API in browsers?

Accepted Answer

To store key-value data persistently in the browser with no expiration

Answer

localStorage stores string key-value pairs in the browser that persist across sessions until explicitly cleared by code or the user.

Question 2

Which CSS selector targets every other even row in a table?

Accepted Answer

tr:nth-child(even)

Answer

tr:nth-child(even) matches every table row whose position is an even number, commonly used for zebra-striping.

Question 3

In JavaScript, what is a closure?

Accepted Answer

A function that retains access to variables from its outer scope even after the outer function has returned

Answer

A closure is formed when an inner function captures and remembers its lexical environment, including variables from enclosing scopes.

Question 4

Which meta tag configures the viewport for responsive design on mobile devices?

Accepted Answer

Answer

The viewport meta tag tells mobile browsers to set the page width to the device screen width and not to zoom out by default.

Question 5

What does the JavaScript `Array.prototype.reduce()` method do?

Accepted Answer

Executes a callback on each element to accumulate a single output value

Answer

reduce() applies a callback function with an accumulator and each element, folding the array down to a single return value.

Front End Development Practice Test