JavaScript – what is it?

JavaScript - definition

JavaScript is a high-level, dynamically typed programming language primarily used to create interactive effects on websites. It is the primary scripting language used in web browsers, allowing for the manipulation of HTML and CSS elements and handling user events. JavaScript is also used outside of browsers due to its versatility and ability to run on servers using platforms such as Node.js. As an interpreted language, JavaScript requires no compilation, allowing for rapid prototyping and rapid iteration in web application development.

History of JavaScript

The history of JavaScript is a fascinating journey through the various stages of development that led to what we know today as one of the most popular programming languages ​​in the world. Here are the key events and milestones in JavaScript's history:

1. Beginnings:

JavaScript was created by Brendan Eich in just 10 days in 1995 while he was working at Netscape Communications Corporation. It was initially called Mocha and later LiveScript.

2. Netscape Navigator:

JavaScript was first included in Netscape Navigator in 1995. It has become the primary scripting language used in web browsers to create interactive web pages.

3. Standardization:

In response to JavaScript's popularity, Microsoft created its equivalent, JScript, which led to the need for standardization. In 1997, JavaScript was standardized by Ecma International as ECMAScript, ensuring its consistent operation across platforms.

4. Era of dynamic development:

Between 2000 and 2010, JavaScript gained popularity thanks to the development of AJAX technology, which allowed dynamic loading of content on websites without the need to reload the entire page.

5. New standards and development:

In the following years, JavaScript underwent continuous development and improvement, resulting in the release of new versions of the ECMAScript standard. ECMAScript 5 was released in 2009, followed by ECMAScript 6 (ES6) in 2015, introducing new features and improvements to the language.

6. Application outside of browsers:

JavaScript is no longer limited to writing scripts for websites. It has been adapted for a variety of applications, including server development (Node.js), mobile applications (React Native), desktop applications (Electron), and the Internet of Things (IoT).

7. Present day:

Currently, JavaScript is one of the most widely used programming languages ​​in the world. A growing developer community, numerous frameworks and libraries, and browser support make JavaScript crucial in today's IT world.

How does JavaScript work?

Here are some key features of how JavaScript works:

• Interpreted: JavaScript code is interpreted line by line, rather than being compiled into machine code before execution. This means that JavaScript code may run faster, but it may also be less efficient than compiled code.
• Dynamically typed: JavaScript variables' types are not declared in advance, but are determined when a value is assigned to the variable. This makes JavaScript a flexible language, but it can also lead to runtime errors.
• Functional: JavaScript is a functional language, meaning its code is organized into functions that can be reused and passed as arguments to other functions. This means JavaScript code can be modular and easy to maintain.
• Event-driven: JavaScript is an event-driven language, meaning its code can respond to user-generated events or other elements of the web page. This means JavaScript can be used to create interactive web applications.

JavaScript structure

JavaScript consists of several key elements that define its structure and operation:

1. Comments:

• Used to explain code without affecting its operation.
• They can be single-line (//) or multi-line (/* */).

2. Keywords:

• Reserved words that have special meaning in the language.
• They define control statements, data types, and other language features.
• Example keywords: var, let, const, if, else, while, function, return, true, false.

3. Identifiers:

• Names used to identify variables, functions, and other language elements.
• They must start with a letter, number, or underscore (_).
• They can contain letters, numbers, underscores, and dashes (-).

4. Literals:

• They represent values ​​directly in the code.
• These can be string literals (with quotes), numeric literals (without quotes), boolean literals (true or false), and object literals ({}).

5. Operators:

• They define operations performed on values.
• There are different types of operators, such as arithmetic (addition, subtraction, multiplication, division), logical (and, or, not), comparison (equality, inequality, less than/greater than), and assignment (=).

6. Instructions:

• They define the actions performed by the program.
• These can be simple statements (e.g. assigning a value to a variable) or complex blocks of statements (e.g. loops, conditional statements).

7. Functions:

• Subroutines that define a block of code that performs a specific task.
• They consist of a function name, parentheses (()), and an optional code block ({}).
• They can accept arguments (values ​​passed to functions) and return values.

8. Objects:

• Collections of ordered key-value pairs.
• They represent real objects with properties and methods.
• They are defined using curly braces ({}) and key-value pairs (key: value).

9. Boards:

• Ordered collections of values.
• They can store different types of data.
• They are defined using square brackets ([]) and comma-separated values.

10. Exceptions:

• Error handling mechanisms in the program.
• Allows you to capture and handle errors during program execution.

Popular JavaScript frameworks

• React: This is a JavaScript library created by Facebook for building user interfaces. React is known for its declarative nature, reusable components, and ease of learning. It's ideal for building dynamic and scalable web applications.
• Vue.js: This progressive JavaScript framework is becoming increasingly popular due to its simplicity and flexibility. Vue.js features the MVC (Model-View-Controller) pattern, which simplifies code organization. It's a good choice for smaller projects or for developers who prefer a more concise framework.
• Angular: This is a JavaScript framework created by Google for building complex web applications. Angular offers a rich component architecture, built-in testing tools, and integration with numerous Google tools. It's a good choice for large projects requiring extensive structure and functionality.
• Svelte: This is a newer JavaScript framework that's gaining popularity due to its unique approach to components. Svelte compiles components into JavaScript code without redundancies, which can lead to smaller and faster applications. It's a good choice for developers looking for a powerful and modern framework.
• Next.js: This is a React framework created by Vercel for building server-side rendering (SSR) and static pre-generated pages (SSG) websites and web applications. Next.js offers many features that facilitate the creation of SEO-friendly websites and fast web applications. It's a good choice for React developers who want to build high-performance websites or web applications.

JavaScript in Shopify

In Shopify, JavaScript plays a crucial role in enhancing the functionality of online stores. You can use it in two main ways:

1. Shopify themes using Liquid:

• Shopify themes are ready-made solutions that allow you to quickly launch an online store. They come with a built-in programming language called Shopify Liquid .
• Liquid allows you to add basic logic and dynamic elements to your templates. You can use it for things like:
  • Displaying products from your catalog
  • Entering logical conditions (e.g. displaying promotions only to logged-in users)
  • Looping through data and displaying it in the appropriate format
• JavaScript Modifications: While Liquid allows for basic logic, more complex operations require JavaScript. You can add JavaScript files to your Shopify themes for greater control over store interactions and functionality.

2. External applications using JavaScript:

• Third-party apps are extensions of your Shopify store's functionality that you can add from the Shopify App Store.
• Many third-party applications use JavaScript to provide interactive features and custom actions within your store. For example, a live chat application might use JavaScript to handle chat and display messages to customers.

Building your own apps: If you have programming knowledge, you can create your own third-party app using JavaScript. Shopify offers an API ( Shopify Rest API ) and developer tools to help you integrate your app with your store.