JavaScript

JS Interview #8: Zero timeout

What if we call `setTimeout` with 0 delay in JavaScript? Which of the messages will be printed first? (think well, then click for the answer and explanation) In JS, `setTimeout(func, delay)` takes a function `func` and delays its execution by `delay` milliseconds....

JS Interview #7: Is this an array?

Let's find out what’s the deal with JavaScript arrays. Is `array` an array? (think well, then click for the answer and explanation) In line one we create an array and bind it with the array constant....

JS Interview #6: Variable number of arguments in JavaScript

`true` or `false`? That is the question... (think well, then click for the answer and explanation) In JS, all functions have access to the internal arguments array that holds all arguments that were passed into the function....

JS Interview #5: Can you use an arrow function as a getter?

Are there any issues with the `getId` function? What will be logged to the screen? (think well, then click for the answer and explanation) So, getId is an arrow function, thus it doesn’t have this of its own....

JS Interview #4: try/catch

How will the `try/catch` blocks behave? What will be logged to the console? (think well, then click for the answer and explanation) So, we have 2 variables and 2 try/catch blocks that supposedly catch errors and put them into e1 and e2....

How to test Node.js backend with `supertest`

So, you’ve built your Node.js backend with Express and now you need a clean and reliable approach to test it? In this article, I’ll show you how you can use the supertest module to make testing your Express.js backend feel like a breeze! ...

Built-in String functions in JavaScript

A detailed review of useful JS functions that will help you work with the String data type. ...

JS Interview #3: Adding strings to numbers and booleans

Will we see any output? If yes, then what would it be? (think well, then click for the answer and explanation) To answer this question correctly, you need to understand the typecast rules in JS....

JS Interview #2: How to create an array in JavaScript

What's the correct way to create an array in JS? (think well, then click for the answer and explanation) The first array, a1 is declared using an empty array literal....

JS Interview #1: Type conversion in JavaScript

What's going to be printed to the console? (think well, then click for the answer and explanation) In the first line, we define the variable `str` and initialize it as a string with the value `1`....