JS (Java Script)
Javascript is one of the most popular and versatile programming languages in the world. It is used to create dynamic and interactive web pages, mobile applications, games, and more. In this blog post, I will introduce you to some of the basic concepts and features of Javascript, and show you how to write your first Javascript program.
What is Javascript?
Javascript is a scripting language that runs in the browser and on the server. It is based on the ECMAScript standard, which defines the syntax and behavior of the language. Javascript can interact with HTML and CSS, manipulate the Document Object Model (DOM), and communicate with web servers and databases.
Javascript is also a high-level language, which means it is easy to read and write, and does not require a compiler or an interpreter. Instead, Javascript code is executed by a Javascript engine, which is embedded in every modern browser and web server.
Javascript is also an interpreted language, which means it is executed line by line, without needing to be converted into machine code beforehand. This makes Javascript fast and flexible, but also prone to errors and bugs.
Javascript is also a dynamically typed language, which means it does not have strict rules about the types of data that variables can hold. Instead, Javascript automatically assigns types to variables based on their values. This makes Javascript expressive and convenient, but also risky and unpredictable.
Javascript is also an object-oriented language, which means it uses objects to store data and methods. Objects are collections of properties and values that can be accessed using dot notation or bracket notation. Objects can also inherit from other objects using prototypes, which are special objects that define the behavior of other objects.
Javascript is also a functional language, which means it treats functions as first-class citizens. Functions are blocks of code that can be assigned to variables, passed as arguments, returned as values, and stored in data structures. Functions can also be nested inside other functions, creating closures that have access to their outer scope.
How to write your first Javascript program?
To write your first Javascript program, you need a text editor and a web browser. You can use any text editor you like, such as Notepad, Sublime Text, Visual Studio Code, etc. You can also use any web browser you like, such as Chrome, Firefox, Safari, etc.
To create a Javascript file, you need to save your code with a .js extension. For example, you can name your file hello.js. To run your Javascript code in the browser, you need to link your Javascript file to an HTML file using a <script> tag. For example, you can create an HTML file named index.html with the following content:
<html>
<head>
<title>My First Javascript Program</title>
</head>
<body>
<h1>My First Javascript Program</h1>
<script src="hello.js"></script>
</body>
</html>
The <script> tag tells the browser where to find your Javascript file and when to execute it. In this case, your Javascript code will run after the HTML content is loaded.
To write your first Javascript program, you need to use the console.log() function. This function prints a message to the browser's console, which is a tool that helps you debug your code. You can open the console by pressing F12 or Ctrl+Shift+I on your keyboard.
To print "Hello World" to the console, you need to write the following code in your hello.js file:
console.log("Hello World");
Save your file and open your index.html file in your browser. You should see "Hello World" printed in the console.
Congratulations! You have written your first Javascript program!
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