What’s the output?

Answer and explanation: https://learn.coderslang.com/js-test-21-iso-date

How toString works in JavaScript?

Answer and explanation: https://learn.coderslang.com/js-test-22-tostring-nuances-in-javascript

How many times can you splice the JavaScript array?

Answer and explanation: https://learn.coderslang.com/js-test-23-splicing-javascript-arrays

Can we add an extra field to a regular JS string?

Answer and explanation: https://learn.coderslang.com/js-test-24-adding-properties-to-strings-in-javascript

How fast is immediate resolve in JavaScript? What’s the output?

Answer and explanation: https://learn.coderslang.com/js-test-25-immediate-resolve

Are these dates equal?

Answer and explanation: https://learn.coderslang.com/js-test-26-date-equality-in-javascript/

In JavaScript you can handle errors in Promise chains using 2 similar approaches.

Is there a difference in them? How do f1 and f2 behave?

Answer and explanation: https://learn.coderslang.com/js-test-27-handling-errors-in-promise-chains/

Jack tried to resolve and reject the Promise at the same time. What did he see in the console?

Answer and explanation: https://learn.coderslang.com/js-test-28-promise-resolution/

What happens if we slice and splice the same array?

Answer and explanation: https://learn.coderslang.com/js-test-29-slice-and-dice

What happens if we try to reject the Promise inside resolve?

Answer and explanation: https://learn.coderslang.com/js-test-30-reject-inside-resolve

What's the output?

Answer and explanation: https://learn.coderslang.com/js-test-31-big-or-small/

How good are you at basic JS calculus?

Answer and explanation: https://learn.coderslang.com/js-test-32-basic-js-calculus/

Let's add two empty arrays and check the type of the result. What's the output?

Answer and explanation:
https://learn.coderslang.com/ru/js-test-33-add-two-empty-arrays-and-check-the-type/

How do you save the current date in JS? What's the output?

Answer and explanation: https://learn.coderslang.com/js-test-34-different-ways-to-get-current-date/

I noticed that a lot of CoderslangJS learners are way too far from the interview prep. No surprises, btw. Learning to code from scratch takes at least half a year.

So I started writing tutorials that help you understand core JavaScript topics. These tutorials are short, concise and always have code examples.

Here’s the first one: https://learn.coderslang.com/0022-how-to-compare-strings-in-javascript

What’s faster, immediate resolve or zero timeout? What’s the order of the output?

Answer and explanation: https://learn.coderslang.com/js-test-35-zero-timeout-vs-immediate-resolve/

JavaScript, how to delay the function execution with setTimeout. https://learn.coderslang.com/0025-javascript-settimeout-delay-the-function-execution/

JavaScript, asynchronous programming and promises: https://learn.coderslang.com/0027-javascript-asynchronous-programming-and-promises