For two million years, Earth has been inhabited by living things that make their own food. Known as the producers of their communities, these self-sufficient life forms convert substances from their immediate environment into energy-rich food molecules.

The energy they pack into these molecules has to come from somewhere — and while we have long known that plants and chlorophyll-carrying microbes harness energy from the sun via photosynthesis, a new type of producer was discovered a bit less than a half-century ago. Curiously, these new specimens live in the complete absence of sunlight — and somehow make their own nutrients.

Chemosynthesis

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For four years, I have been building Android applications that talk with other systems via JSON APIs — usually one-way or two-way handshakes between my app and a Drupal site or database using JavaScript Object Notation (JSON) as the common language.

My first encounter with JSON

I first started using JSON in the Spring of 2012 after taking a web development course. Before then, my programs were pulling in XML content files. They got the job done, but they felt a bit clunky.

I remember the day our instructor introduced us to JSON. …

If you’re a seasoned developer, you’ve likely wrestled with bugs time and again. If you’re new to web or app development, just wait.

These are the ones that are the thorn in your side.

The ones that keep you up at night—or greet you in the morning when you check the ticketing system.

You may have encountered one lurking in the shadows on a course project, during a migration, or while modifying a new build. What these bugs all have in common is that finding and fixing them is akin to trying to scale an insurmountable stone wall.

But there…

The tech world is replete with interoperable systems that communicate data back and forth. While each system has its own inner workings, two systems can talk to each other if they both use a common language. One of these languages is JSON (JavaScript Object Notation), a lightweight format for storing and sending data that consists of key-value pairs.

As a simple example, you may have an app that needs to download the following JSON data on two books from a content management website. The books may look like this:

{
  "books":[
    {…

While mitosis and meiosis are very similar-sounding processes, they are actually quite different — and occur for different reasons.

Suppose you fall and scrape your knee. You will likely see your wound heal over the next few weeks as your body tissue repairs itself, and that is in large part due to mitosis.

In contrast, meiosis is the reason why people often look partially look like one of our parents — as due to meiosis, they only inherit half the DNA from each parent.

Let’s take a closer look at each process.

Mitosis

Mitosis occurs during the division of body cells…

Star rating tools are seen on all kinds of apps and websites these days. Who knows — at one point you may be asked to build one as a quick way to collect user feedback.

Below is one way of achieving the star rating effect using pure CSS. You can glance at the finished product below.

Along the way, you’ll learn to use pseudoselectors, the “subsequent siblings” combinator (~), a few flexbox layout techniques, and a CSS transition.

While this code is Javascript-free, you will ultimately want to use some programming to parse, send, and store the value that…

Very helpful read, Nehal. I like your use of diagrams and brief gists to convey the code and the concepts. I use JS just about every day and this helps me to better understand what's happening under the hood.

There is a reason why oil and water do not mix — and why some compounds, like sugar, dissolve in water easily.

The answer lies in solubility — how easily one substance, a solute, dissolves in another substance — the solvent. When the solubility of a compound is discussed and the exact solvent is not mentioned, it usually means that the solvent is water.

A molecule’s solubility is determined by its degree of polarity. …