Variable values have certain types. In fact, you can cast a value of one type to the other. If you do it explicitly, it is type casting (also called explicit coercion). If it happens in the background when you are trying to perform an operation on types that do not match, it is called coercion (sometimes referred to […]
We covered quite a few features of regex so far. There is a lot more, though. Today we will deal with more advanced concepts, like groping and cover more of the RegExp object features in JavaScript. We will also learn how to use some of the features that ES6 brought us. Let’s go! exec It […]
Hello again! Today we are back to regular expressions in JavaScript. If you are new to them, check out the first part of the course. This time we will learn how to write more elegant patterns and define the position of searched strings. The shorter way to define repetitions Recently we’ve learned, that the asterisk, […]
Regular expressions (regex) are sequences of characters defining a search pattern. Since it can be extremely useful in programmers everyday life, it was implemented into JavaScript. In this series of articles, I will show you how it works and what are its real-life usages. Hopefully, by the end of this part of the course, you […]
Generators are a new feature introduced in ES6, and as I’ve promised in the article about async/await last week, we will cover them today. Iterators In JavaScript an iterator is an object that provides a next() method which returns the next item in the sequence. The first concept to understand here is the iterator. You might […]
Back in the days, we used callbacks. Then, we were blessed with promises. The journey does not stop there, though. ES7 introduced us to a new way of handling asynchronous calls: async/await. Feel free to read my other articles if you would like to know more about async in general, or callbacks and promises. The purpose […]
There is a good chance that you are already using promises in your code – they are everywhere now. Have you ever considered how they work, though? I this article I want to explain why they are a good thing and what problems do they solve. I will do that while implementing quite a ludicrous sorting […]
You can think of a scope as of a wrapper that contains all the variables and a reference to the parent scope. What does that mean and what should we watch out for when dealing with it? Let’s find out! How scopes work When we try to access a variable in our code, the interpreter […]
One of the great things that ES6 brought us are classes. We need to remember though, that all the work is done by prototypes under the hood. It means that ES6 classes act just as syntactic sugar. In this article, I will walk you through the basics of the prototypes, so that you can better grasp […]
Undefined is one of the reasons for confusion and can get under the skin of a developer. But what is it exactly? Definition of undefined It is a value undefined value primitive value used when a variable has not been assigned a value Undefined is a special value that lets the programmer know that a variable […]