[javascript]

21 Nov 2023

javascript

JavaScript is a widely-used programming language for building interactive websites and web applications. It is primarily used for client-side development, meaning it runs on the user’s web browser.

Getting started with JavaScript

To start using JavaScript in your web page, you can include the <script> tag in your HTML code. Here’s an example:

<!DOCTYPE html>
<html>
<head>
  <title>My First JavaScript Page</title>
</head>
<body>

<h1>JavaScript Demo</h1>

<script>
  // Your JavaScript code here
  alert("Hello, JavaScript!");
</script>

</body>
</html>

In the example above, the JavaScript code within the <script> tag is executed when the web page is loaded, and it displays a popup alert with the message “Hello, JavaScript!”.

Variables and Data Types

In JavaScript, variables are used to store data. You can declare a variable using the var, let, or const keyword. Here’s an example:

var myVariable = 10; // Number
let myString = "Hello, JavaScript!"; // String
const PI = 3.14; // Constant

JavaScript has various data types including numbers, strings, booleans, arrays, objects, and more.

Control Flow and Loops

JavaScript provides control flow statements like if, else if, else to perform conditional operations. Here’s an example:

let age = 25;

if (age < 18) {
  console.log("You are a minor.");
} else if (age >= 18 && age < 65) {
  console.log("You are an adult.");
} else {
  console.log("You are a senior citizen.");
}

JavaScript also has loop structures like for and while for repeated execution of code blocks. Here’s an example of a for loop:

for (let i = 0; i < 5; i++) {
  console.log(i);
}

This will output the numbers from 0 to 4.

Conclusion

This is just a basic introduction to JavaScript. There’s much more to learn and explore in JavaScript. I recommend referring to the Mozilla Developer Network (MDN) for detailed documentation and tutorials on JavaScript. Happy coding!