Javascript language is de-facto standard for making client-side web applications that consume different kinds of APIs. It can even be used for mobile applications thanks to wrapper frameworks such as Apache Cordova, React Native, or NativeScript. You can even use it with gaming frameworks like Cocos 2D, Unity, or many others. Almost all games published in recent few years, especially for mobile phones can also be classified as client-side applications that interact with server-side sending and receiving data such as score, in-game positions, moves, and many others to the server through an API.

But let’s take a look at a simple example of Javascript client application that consumes an API using a built-in fetch function.

…

In Javascript we have a couple of options for checking equality, so let’s take a look at them – what are similarities, and what are the differences.
…

What is null in Javascript?

In JavaScript the value null represents the intentional absence of any object value. The value null is one of JavaScript’s primitive values and is treated as falsy for boolean operations. We could compare a value null to a similar primitive value – undefined. Undefined is an unintentional absence of any object value, and this “unintentional” is the thing that differentiates null from the undefined.
…

The beauty of PHP is that you can do one thing in several different ways. And, yes, this is the case with PHP arrays too – they can be merged using the + array union operator or you could use the array_merge() function. However, there is a difference between array_merge and array + array, so let’s take a look at the functions we’re are dealing with.
…

This article is going to focus on the comparison operator known as Equal Operator and presented as “==” or double equal sign, and the inbuilt strcmp() function. We are going to look at the differences and similarities between these two.
…

What if you are developing an application that requires a client to upload a file or an image and information about the image via RESTful API and you want the client to send data as JSON? The easy answer would be to perform two posts to REST API.
But is that even possible in a single request?
…

You might get into a situation where you need to hook some PHP function. There are many reasons why you might need to do that. One of the most obvious cases is debugging. In PHP it is really easy to hook any function using override_function which overrides built-in functions. However, these simple “hacks” are practical only in conditions when you’re dealing with your own code or some relatively simple code you can change with ease.

In a more complex situation, like if you need to hook the PHP mail function without messing with some third-party source code you need to do it a bit differently.
…

Recently I’ve been running into problems trying to save JSON in the MySQL database. Even though MySQL supports JSON type for a while now, there are still plenty of gotchas while you work with it. The situation is pretty critical with special characters. This time we are going to be short and on the topic of invalid JSON characters.
…

You could come into a situation where you are dealing with HTML special characters in some text. Ordinary users might not even notice these special characters exist because when they take a peek at a text in a browser these characters look exactly like normal characters do. However, if you – an advanced user – take a look into the page source, you’ll notice some very unusual presentations, (&amp; for &, &quot; for “, &lt; for <, &gt for > and so on). So, the question is – how do you convert this mumbo jumbo to normal characters?
…

As you probably know it’s possible to install multiple versions of PHP on one server. For web servers, simply define which PHP version you want to use in your server’s configuration file. But how to do it for PHP cli?
…