Frontend

What is the context (this) in JavaScript?

Should you write logic in React components, move it to hooks, or try to keep business logic outside React? What is your view on this?

How to determine that let and const are hoisted (hoisting) even though they are in the Temporal Dead Zone?

Determine the order of output in console.log for the given JavaScript code fragment with functions foo/bar, Promise, and setTimeout.

LeetCode #125 — Write a function that determines whether a string is a palindrome: whether it reads the same from the beginning and the end.

Have you used libraries for runtime validation and type assertion, for example, for checking data received from APIs?

Have you used Set and Map collections in ES6? Tell us about them.

What is the difference between a regular function and an arrow function in JavaScript?

Which do you like more: any or unknown?

Why is it necessary to use keys for an array of components with internal state? What can happen with incorrect keys or their absence? How do keys affect the internal state of components?

What is Promise in JavaScript?

Write a function to execute an array of asynchronous tasks with a limit on the number of tasks running simultaneously; results should be returned in the order of the original task array, regardless of completion order.

Write the simplest way to check for a palindrome without a for loop — for example, using split, reverse, and join.

What is hoisting in JavaScript?

Tell about Event Loop as a concept.

Can you use an arrow function as a constructor?

Tell about any and unknown in TypeScript.

What is Virtual DOM in React?

Tell about the lifecycle of React functional components and how to connect to it.

How to avoid prop drilling? Is prop drilling a problem?