How Asynchronous Javascript Transforms Web Development

What is Asynchronous? Asynchronous is when you can do multiple tasks at a time without them delaying each other. You wake up in the morning, you go to the kitchen to put your food on the stove frequently checking it for it not to burn, you put your clothes in the washing machine and then set the timer, after that, you start to get your clothes ironed.

You are also performing asynchronous operations because you don’t have to wait for the food to be done before getting your clothes washed in the washing machine and then ironing your clothes. If you are to wait for you to do all this one after the other. It will take time and you may even get tired.

Asynchronous programming is when multiple tasks are done at the same time in a program or executed at the same time rather than them running one after the other.

How does Javascript become asynchronous?

Javascript has one thread of execution so it can do only one thing at a time. They are not like other programming that are multi-thread like Java.

Javascript has a runtime that comprises the javascript engine, Web API, and the call back queue.

The javascript engine has a Call stack inside of it.

The code written is compiled in the call stack, which is inside the engine. All call-back functions are placed, inside the callback Queue in the order of who comes first.

Now, this is where it all comes into play. Once the code in the call stack is executed then we have the EVENT LOOP. The EVENT LOOP makes asynchronous possible in JavaScript. The EVENT LOOP checks the call stack to know if it's empty or to ensure all the code has been executed.

Once it's empty the EVENT LOOP takes the first call-back function in the call-back queue it sees and takes it to the call stack where it is being executed. It repeats this task until the callback queue is empty then this stops. This is how Javascript enables asynchronous code.

The question now is how does it Transform Web development?

IMPROVED RESPONSIVENESS

It helps improve responsiveness in web development by allowing tasks to be done independently of the program flow. For example, Not waiting for us to get something from the server before other parts are shown to the user. It's achievable through callback functions, promises, and async/await.

Let's take a look at this code:

In this example, fetchData function uses the fetch API to make an asynchronous request (non-blocking request). This program does not wait for the fetch API to finish executing before it continues executing other operations. When the API responds the try and catch block code will handle the data and error.
EVENT-DRIVEN PROGRAMMING

Asynchronous operations are tied to an event-driven programming model, where actions or occurrences (events) trigger the execution of specific functions.

Example:

Once this code is executed,

The addEventListener method is used to register an event listener on the 'click' event of the specified HTML element.

it stores the callback function in the callback queue and waits for the event to take place. Once it takes place the call-back function is called so it is driven by the click event.
REAL-TIME APPLICATIONS

Real-time functionality in web development typically involves updating the user interface or exchanging data with the server immediately as events occur, without you refreshing the page. Asynchronous operations play a crucial role in achieving real-time behavior.
NODE.JS AND SERVER-SIDE JAVASCRIPT

Asynchronous operations play a crucial role in server-side web development, allowing servers to efficiently handle multiple tasks simultaneously without blocking the execution of other code. This non-blocking nature is essential for building scalable and responsive web applications.

We have learned the few ways asynchronous javascript helps transform web development.

If you enjoyed this, kindly leave a like, and follow for more technical content.