JS ( Java Script ) - Programmer Bhed

JavaScript is a programming language that is primarily used to create interactive and dynamic websites. It is a client-side scripting language, which means that the code is executed on the user's computer, rather than on a server. This allows for faster response times and a more seamless user experience.

One of the key features of JavaScript is its ability to manipulate and update the Document Object Model (DOM) of a web page. The DOM is a tree-like structure that represents the elements of a web page, such as text, images, and buttons. By manipulating the DOM, JavaScript can change the appearance and behavior of a web page without requiring a full page reload.

JavaScript is also commonly used for a wide range of other tasks, such as form validation, data manipulation, and working with web APIs. The language is supported by all major web browsers, including Chrome, Firefox, Safari, and Edge.

The basic syntax of JavaScript is similar to other programming languages, such as C and Java. It uses variables to store and manipulate data, and includes a wide range of data types, including strings, numbers, and booleans. JavaScript also supports functions, which are blocks of code that can be executed multiple times.

Here's a simple example of JavaScript code that can be used to change the text of a webpage:-

    var heading = document.getElementById("myHeading");
    heading.innerHTML = "Hello, JavaScript!";

In this example, the code first selects an element on the page with the id "myHeading" using the getElementById() method. It then changes the text of that element to "Hello, JavaScript!" using the innerHTML property.

JavaScript also have many libraries and frameworks available to make our life easy and improve the development speed such as jQuery, AngularJS, ReactJS, and VueJS are the most common among them.

JavaScript continues to be one of the most popular programming languages in use today, and is an essential skill for any web developer. It's relatively simple to learn and its capabilities are constantly evolving, so its definitely worth learning.

What Is ECMAScript ?

ECMAScript is the official name for the standard upon which JavaScript is based. It is a scripting language specification developed by the European Computer Manufacturers Association (ECMA). JavaScript, JScript, and ActionScript are all dialects of ECMAScript.

ECMAScript defines the syntax and semantics of the language, as well as the basic objects and their properties. Each version of ECMAScript, often referred as ECMAScript version, adds new features and capabilities to the language.

The current version of ECMAScript is ECMAScript 2020, which was officially published in June 2020. Some of the new features in ECMAScript 2020 include optional chaining, nullish coalescing, globalThis and more.

The next version, ECMAScript 2021 (ES2021), which was released in June 2021. It includes new features such as Promise.any, String.prototype.matchAll, WeakRef and FinalizationRegistry.

ECMAScript standards are an ongoing process, and new versions are regularly released to keep the language up-to-date and relevant. Some of the features that are expected to be added in future versions include modules, class-based inheritance, and template literals.

It is important to notice that not all features are supported by all the browsers and we need to check the browser compatibility for features before using them. There are also transpiler and polyfills that can be used to add support for new features on old browsers.

JavaScript Syntax

JavaScript has a C-style syntax, which means that it uses curly braces to define blocks of code and semicolons to separate statements.

JavaScript also uses the following basic elements:-

1. Variables: Variables are used to store and manipulate data. You can declare a variable using the var, let, or const keyword, like this.

var x;
let y = 3.14;
const z = "Hello, JavaScript!";

In recent versions of JavaScript, using let and const are more encouraged than using var. let allows to reassign variable's value but const doesn't.

2. Data Types: JavaScript has a variety of data types, including strings, numbers, booleans, and more.

var name = "Programmer Bhed";
var age = 18;
var isStudent = true;

3. Operators: JavaScript includes a wide range of operators, such as arithmetic operators, comparison operators, and logical operators.

var x = 3;
var y = 4;
var sum = x + y;
var isGreater = x > y;

4. Conditional Statements: JavaScript supports the use of if-else statements to control the flow of a program.

if (x > y) {
  console.log("x is greater than y");
} else if (x < y) {
  console.log("x is less than y");
} else {
  console.log("x is equal to y");
}

5. Loops: JavaScript also supports the use of loops to repeat a block of code multiple times. The most common loops are for, while and do-while.

for (var i = 0; i < 10; i++) {
  console.log(i);
}

6. Functions: Functions are blocks of code that can be executed multiple times.

function add(x, y) {
  return x + y;
}
console.log(add(3, 4));

This is a very brief overview of JavaScript syntax, but it covers the basics. JavaScript also has more advanced features like object-oriented programming, regular expressions, and error handling,

It's a good idea to practice writing and experimenting with JavaScript code to become more familiar with the syntax and its capabilities.

JavaScript Libraries & Frameworks

JavaScript libraries and frameworks are collections of pre-written JavaScript code that can be used to add functionality to web projects. Some popular JavaScript libraries and frameworks include:-

• jQuery: A widely-used library that makes it easier to work with HTML documents, handle events, create animations, and develop cross-browser compatible applications.
• AngularJS: A framework developed by Google that allows you to build complex web applications using a component-based architecture.
• React: A library developed by Facebook for building user interfaces, with a focus on performance and flexibility.
• Vue.js: JavaScript framework that is easy to learn and integrate with other libraries or existing projects.
• Ember.js: A framework for building ambitious web applications, it was designed to have a strong conventions and provide best practices for web development.
• Backbone.js: A lightweight framework that gives structure to web applications by providing models with key-value binding and custom events, collections with a rich API of enumerable functions, views with declarative event handling, and connects it all to your existing API over a RESTful JSON interface.
• Lodash: A library that provides a wide range of utility functions for common tasks such as manipulating arrays and objects, working with numbers and strings, and handling asynchronous code.
• Moment.js: A library for working with dates and times, which makes it easy to parse, validate, manipulate, and format dates.
• D3.js: A library for creating interactive data visualizations, which uses web standards such as SVG, HTML, and CSS.
• Chart.js: A simple and flexible JavaScript charting library that allows you to create different types of charts, including bar charts, line charts, and pie charts.
• Webpack: A JavaScript module bundler, it can help you optimize assets, manage and transform a big amount of files of your projects, and provide an easy solution to configure.
• Next.js: A framework for building server-rendered React applications, it's designed for building production-ready web apps with automatic code splitting, server-side rendering, and static site generation.
• Nest.js: A framework for building scalable and maintainable server-side applications with Node.js, it's built on top of Express.js, and uses TypeScript.
• Svelte: A lightweight JavaScript framework that allows you to build web applications with a simple syntax and small bundle size.

How To Execute JavaScript ?

JavaScript can be executed in a variety of ways, depending on the context. Some of the most common ways to execute JavaScript include:-

• In Web Browser: JavaScript is primarily used to create interactive and dynamic web pages. When a web page is loaded in a browser, the JavaScript code within the page is automatically executed by the browser's JavaScript engine.
• In JavaScript Console: Most modern web browsers have a JavaScript console that can be accessed through the developer tools. The console allows you to type in and execute JavaScript code directly, which can be useful for testing and debugging.
• In Script Tag: JavaScript code can be included in an HTML file within script tags. This code will be executed when the page is loaded by the browser.
• Using JavaScript Library Or Framework: JavaScript libraries and frameworks, such as jQuery or AngularJS, provide a set of pre-written functions that can be called to perform specific tasks.
• Using Build Tool: JavaScript can also be executed via a build tool, such as webpack, which can help to bundle, optimize and transpile the code.
• In Node.js: Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. It allows you to run JavaScript code on the server-side, allowing you to build command-line tools and server-side applications.

In general, you can execute JavaScript code by adding it to an HTML file and running it in a web browser, or by running it in a JavaScript runtime environment such as Node.js.

Benefits Of Learning JavaScript

There are several benefits to learning JavaScript:-

• Popularity: JavaScript is one of the most widely-used programming languages in the world, and is the primary language used for client-side web development. This means that there is a high demand for JavaScript developers and many job opportunities available.
• Versatility: JavaScript can be used for a wide range of tasks, including creating interactive and dynamic user interfaces, building web and mobile apps, and creating backend services with Node.js. This makes it a valuable language to know for full stack development.
• Large Ecosystem: JavaScript has a large and active community, with many open-source libraries and frameworks available that can be used to accelerate development and add functionality.
• Learn Once, Write Anywhere (LOWA): JavaScript is a cross-platform language and can be used on a variety of devices and environments, such as servers, browsers, desktop and mobile apps.
• Interoperability: JavaScript can interact with other technologies such as HTML and CSS, so it's a great choice for building complex and interactive websites.
• Access To Emerging Technologies: The JavaScript community is constantly pushing the boundaries of what's possible with the language, and as a result, there are many exciting new technologies, such as web assembly, web workers, service worker, web components, and web animations that are only available to JavaScript developers.

Overall, learning JavaScript is a valuable skill for anyone interested in web development, and can open up a wide range of job opportunities.

Example Of Basic JavaScript Code

// Declare a variable
let message = "Hello, World!";

// Output the value of the variable to the console
console.log(message);

// Perform a mathematical calculation
let x = 5;
let y = 10;
let result = x + y;

console.log(result);

// Create a function
function greet(name) {
  console.log("Hello, " + name + "!");
}

// Call the function
greet("Bhed");

// Conditional statement
let age = 25;
if (age >= 21) {
  console.log("You can drink alcohol.");
} else {
  console.log("You cannot drink alcohol.");
}

This code demonstrates how to:-

1. Declare a variable using the let keyword and assign it a value.
2. Output the value of a variable to the console using console.log()
3. Perform a mathematical calculation and assign the result to a variable
4. Create a function that takes an argument and outputs a string
5. Call a function passing an argument
6. Use a conditional statement to check if the value of a variable is greater than or equal to a certain value and output a message depending on the result.

This is just a small sample of what's possible with JavaScript, but it gives you an idea of some of the basic concepts that are used in writing JavaScript code.

Example Of Advance JavaScript Code

// Import a module
import axios from 'axios';

// Make an API request
axios.get('https://jsonplaceholder.typicode.com/todos/1')
  .then(response => {
    console.log(response.data);
  })
  .catch(error => {
    console.log(error);
  });

// Use Array.map method to transform an array
let numbers = [1, 2, 3, 4, 5];
let doubledNumbers = numbers.map(number => number * 2);
console.log(doubledNumbers);

// Use arrow functions and destructuring
const todos = [
  { id: 1, text: 'Clean the house', completed: true },
  { id: 2, text: 'Buy groceries', completed: false },
  { id: 3, text: 'Finish work project', completed: false },
];

const activeTodos = todos
  .filter(({ completed }) => !completed)
  .map(({ id, text }) => ({ id, text }));

console.log(activeTodos);

// Use classes
class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }

  speak() {
    console.log(`My name is ${this.name} and I am ${this.age} years old.`);
  }
}

let bhed = new Person("Bhed", 19);
bhed.speak();

This code demonstrates how to:-

1. import a module using ES6 import statement, in this example it's the axios library
2. Make an API request using axios library
3. Use the Array.map() method to transform an array by applying a function to each element.
4. Use arrow functions, destructuring and filter array method to filter the todos list
5. Use a class and constructor to create and instance of an object, and use a method in the class

This is a more complex example that shows some of the more advanced features of JavaScript and how they can be used to write more sophisticated code.

Make An Artificial Intelligence (AI) Using JavaScript

There are many ways to write AI code using JavaScript, as the language is well-suited for both machine learning and natural language processing tasks. Below is an example of a simple AI program that uses the library TensorFlow.js to train a neural network to recognize handwritten digits. This example uses the MNIST dataset, which is a dataset of 60,000 28x28 grayscale images of handwritten digits and their corresponding labels (0-9).

const tf = require('@tensorflow/tfjs');

// Load the MNIST dataset
const mnist = require('mnist-data');
const dataset = mnist.training(0, 60000);

// Create a neural network model
const model = tf.sequential();
model.add(tf.layers.dense({ units: 512, activation: 'relu', inputShape: [784] }));
model.add(tf.layers.dense({ units: 10, activation: 'softmax' }));

// Compile the model
model.compile({
  optimizer: 'sgd',
  loss: 'categoricalCrossentropy',
  metrics: ['accuracy']
});

// Prepare the data for training
const xs = tf.tensor4d(dataset.images, [dataset.images.length, 28, 28, 1]);
const labels = tf.oneHot(tf.tensor1d(dataset.labels, 'int32'), 10);

// Train the model
model.fit(xs, labels, {
  epochs: 10,
  callbacks: {
    onEpochEnd: (epoch, log) => console.log(`Epoch ${epoch}: loss = ${log.loss}, accuracy = ${log.acc}`)
  }
});

The above code loads the data, build the model, compile it and trained the model. It will take around 10 Epochs to train the model with accuracy around 92% and loss around 0.28.

This is just one example of how AI can be implemented using JavaScript, and there are many other libraries and techniques that can be used. Some other popular libraries include Brain.js, Synaptic.js, and Deeplearn.js.

How "Programmer Bhed" Will Help You To Learn JavaScript

"Programmer Bhed", a programming coaching center, can help students learning JavaScript in a variety of ways:-

• Expert Instructors: The center will likely have experienced instructors who are well-versed in JavaScript and can provide guidance and mentorship to students as they learn the language.
• Curriculum: The center will have a structured curriculum that is designed to help students progress through the material at a steady pace, and covers all the important concepts and best practices in JavaScript.
• Hands-On Practice: The center will likely provide students with plenty of opportunities to write and work with JavaScript code through a variety of exercises and projects. This is an important aspect of learning as it helps to solidify the concepts and gain practical skills.
• Access To Resources: The center may have access to a wide range of resources such as tutorials, videos, and books that can be used to supplement the learning.
• Networking Opportunities: The center may have a community of students and alumni who can provide support and networking opportunities as the students progress through the program.
• Personalized Feedback: The center will provide personalized feedback, that can help the students to better understand their strengths and weaknesses, and identify areas for improvement.
• Flexibility: The center might offer flexible scheduling, allowing the students to balance their learning with other commitments such as work or family.

Overall, "Programmer Bhed" can provide students with a structured, supportive, and hands-on learning environment that can help them to become proficient in JavaScript and be prepared for job opportunities in the field.