Write Parameterized Tests In Jest
Unit tests are crucial - they help to confirm that the individual parts of applications work as intended. On the one hand, without them you are never sure that everything works correctly, whether after refactoring or adding a new feature. On the other hand...Read more
How To Validate An Email Address In JavaScript?
Web applications should prevent a possibility of entering incorrect data, especially if it is such important information as email address. Email address validation is a must for all websites, not only to prevent fake data from being sent to the...Read more
Mean, Median, Mode and Range In JavaScript
Calculating mean, median, mode and range isn't a very common task, but developers definitely need to know what they are and how to calculate them based on a set of numbers. Before we proceed with the implementation, let's learn...Read more
Factorial Of A Number In JavaScript
Factorial of a number is a non-negative integer calculated as the product of all positive integers less than or equal to the number and is denoted by n!. For example: 10! = 10 \* 9 \* 8 \* 7 \* 6 \* 5 \* 4 \* 3 \* 2 * 1 = 3628800. It can be represented by the following formula...Read more
Fibonacci Sequence In JavaScript
Fibonacci Sequence is a sequence of numbers in which each number is a sum of the previous two, starting with 0 and 1. The example sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, etc. It can be represented by the following formula...Read more
Replace All String Occurrences In JavaScript
Replacing all occurrences of a string is a fairly common task in JavaScript. I would not believe you if you said that you have never written any code to replace underscores with hyphens or vice versa. There are a few ways to do that...Read more
Promise.any() And AggregateError In JavaScript
Nowadays, due to the increasing popularity of asynchronous programming, Promises have become an essential part of software engineer's daily routine. Promise is an object that produces a value in the future, which represents the result of an asynchronous operation. It has 3 states...Read more
3 Ways To Mock Axios In Jest
Every developer should know how to create a function that makes an API request, and how to test it properly. While creating such a function is a relatively simple task (if you use a good HTTP client, like Axios), testing it requires some effort. It's not always good practice to...Read more
Logical OR/AND/Nullish Assignments In JavaScript
The latest JavaScript specification, ECMAScript 2021, includes a lot of useful features, but the one we'll discuss today is Logical Assignment Operator, which is a combination of a logical operator (||, &&, ??) with an assignment (=)...Read more