## Did your team define own code deprecation strategy?

I didn’t always work in a larger team. At the beginning of my journey as a computer programmer, I was the only one person in a project. It meant that I had had a free-hand (or semi-free-hand) to choose how I could write a code and which solutions I could use. From day to day I could perform a little revolution in the codebase. No consequences and no problems because the only user of the code was me.

Although this situation might look as the best case for a programmer, it doesn’t. Especially for the junior programmer. You have no opportunity to learn from someone else. You can’t validate your ideas and thoughts with others. Ultimately your only friends and co-workers are Google and Mr. StackOverflow.

After some time, I got a new job and I started to work as a part of the team. As a new person in the company, I had tons of ideas and tools that we could use in a project to make our work better, more pleasant and easier. It was relatively easy to introduce new features into the codebase. On the other hand, it was almost impossible to remove the old ones. Why?

Because we didn’t have the code deprecation strategy.

## Don’t use properties and methods from outside the interface

It may sound obvious or even weird for people who programming in statically typed or compiled languages. In my work, I use PHP which is a dynamically typed language with optional strict typing introduced in version 7. At the beginning of my journey with PHP, I didn’t care so much about typing. I had a trivial cause — they didn’t exist yet.

I used to write a code without thinking about types. It was convenient and fast. Furthermore, it allowed writing proxy functions which recognize parameters type and it runs the proper function. Yes, overriding doesn’t exist in PHP.

But things changed when I discovered polymorphism. The magic keyword Interface that allows us to define the mandatory set of features in the object. The picture of writing a code without worrying about missing methods was incredible. I still didn’t understand one thing yet. How interfaces help me since I can pass everything on the function call?

This question lied a long time in my head until I discovered I can define the required type of passed object. Since that time, I changed completely the way how I write the code.

## Building the associative array – ideas

When we talk about arrays we usually mean the vector of something – primitives, objects or even arrays. But there are a lot of situation when we need to carry extra information with our data. We can use nested arrays but it doesn’t cause that the specific item within the array will be easy to identify. To achieve it we should use custom keys. They provide easy access to any element of the array as long as we know the key corresponding with that value.

There are some reasons why we can use associative arrays instead of simple vectors, e.g. readability. Named keys are also more meaningful than numeric indexes. Instead of thinking about the whys, image the situation when we could use a hashmap. Let’s focus on how we can build the associative array from a vector.

## What is idempotence?

If you frown after reading idempotence, don’t worry. Although this word sounds unusual it conceals a simple mathematics property. Needless to say, this characteristic has also a big meaning in Computer Science.

Idempotence operation is an operation that can be applied multiple times without changing the result beyond the initial application. It may sound difficult but after a couple of examples, the general concept will be obvious.

## Why should you return early?

When I started my journey as a computer programmer I had written my code in a various way. I met some condition and I just put the correct statement regardless of the general concept or something more deeply. “It works, that’s it” – and the code base grew and grew in time. Thousands of written methods later I had discovered that a lot of these little pieces of logic could look better if I reverse some condition within them. Unconsciously, I’ve started following the rule which I had later called the “fail fast” rule.

I realized I hadn’t had the one way to check conditions within the single method. Sometimes I let execution if the expression was true. Another time I had waited for the false result to show the error message before the main part of the code was executing. In my head, I discovered various styles of checking conditions.

I remember how I was excited discovering how much frontend frameworks like AngularJS could make my work easier. Even though I was a strong backend-oriented programmer I decided to learn the concept of Angular. I dug into it at ease and I started using this tool in my daily work.

Since I changed my job I lost the opportunity to use frontend technologies regularly. However, I’m still fascinated about this part of software development and I follow trends and latest changes. Therefore AngularJS 1.x was officially abandoned I started looking for something new and fresh.

I didn’t look for a long time. When I first saw React library, I fall in love with it. I quickly caught the concept behind this tool, thanks to ubiquitous tutorials and examples. I read a lot about the flux pattern, redux, components but I didn’t chance to use them in something more ambitious than <HelloWorld/> component. Till now.

## Why you should use array functions instead of basic loops

Loop is the basic construction in each programming language. All repeatable operations are being done using loops. I think you know how the basic loops like whiledo and for work and when you should use one of them. But are you sure? Maybe should you use array functions?

How many of your operations in a loop rely on building objects based on the value? Or selecting only a few items from the array using a predicate? Maybe you use array values to calculate something? Whatever you do, read why you should replacing basic loops by array operations.

## Arguments in arrow function explained

ECMAScript 6 has an amazing feature called Arrow Function. It allows writing a function expression faster and smarter than traditional way (using function keyword). Worth to know, it’s not a one to one replacement for standard functions.

## Blackboxing JavaScript using Chrome DevTools

Lots of JavaScript projects use a dozen of various frameworks, libraries, and third-party scripts. More often code which you produce largely depends from vendors’ work. The good example is jQuery and Lodash libraries which are involved in our pretty code. They are designed to facilitate the work and they are the remedy for especially commonly used, repeatable pieces of code.

This kind of libraries (and frameworks) provide an another abstraction layer behind our code making the execution process more complex. It’s invisible until you’ll need to debug your code because of errors.

## Try explain the JavaScript’s truth inconsistency

Everyone has an own version of a truth. I have the own truth, you have your own. JavaScript has many truths and it’s probably no problem until you’ll start to use it implicitly. This article shows and explains one of the popular JavaScript’s trap – inconsistent evaluation in If Statement and Equality Comparison.