Node.js is an open-source, cross-platform runtime environment that allows you to run JavaScript code on the server side. This means you can build server applications using JavaScript, which is traditionally a client-side language.

Here's a simple example of a Node.js server:

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const http = require('http');

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello, World!\n');
});

const PORT = 3000;
server.listen(PORT, () => {
  console.log(`Server running at http://localhost:${PORT}/`);
});

In this code, we create a basic web server that responds with "Hello, World!" when accessed. You can run this code using Node.js to see it in action. For more information, you can visit the Node.js website.

Node.js is an open-source server-side runtime environment that allows developers to run JavaScript on the server. It uses the V8 JavaScript engine, which is the same engine that powers Google Chrome. With Node.js, developers can build scalable and efficient web applications, server-side APIs, and server-side scripts. It provides a rich set of modules and libraries that make it easy to handle network connections, file systems, databases, and other functionalities commonly used in web development.

Here is the official website of Node.js: https://nodejs.org/

Example code in JavaScript using Node.js:

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// Hello world example in Node.js
console.log("Hello, World!");

Yes, that's true. instanceof operator in JavaScript is used to check the type of an object at runtime. It returns true if the object is an instance of a particular class otherwise it returns false. Here's an example:

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

const john = new Person('John', 25);

console.log(john instanceof Person); // true
console.log(john instanceof Object); // true (since Person is a type of Object)

In this example, we create a new instance of the Person class and use the instanceof operator to check if it's an instance of the Person class or not. The first console.log statement returns true since john is an instance of Person class which means it has name and age attributes defined in the Person constructor. The second console.log statement returns true since Person is a type of Object. Note that instanceof only works with objects not with primitive data types like string, boolean, etc.

Bubble sort is a sorting algorithm that repeatedly compares adjacent elements in a collection of items and swaps them if they are in the wrong order. It is called "bubble sort" because the smaller elements rise to the top of the collection like bubbles.

In terms of runtime, bubble sort has a worst-case and average-case time complexity of O(n^2), where n is the number of elements in the collection. This means that as the size of the collection increases, the time taken to sort it also increases exponentially.

Here's an example implementation of bubble sort in Python:

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def bubble_sort(arr):
    n = len(arr)

    # Traverse through all elements in array
    for i in range(n):

        # Last i elements are already sorted
        for j in range(0, n-i-1):

            # Swap if the element found is greater than the next element
            if arr[j] > arr[j+1]:
                arr[j], arr[j+1] = arr[j+1], arr[j]

    return arr

In this implementation, we have an outer loop that iterates over all the elements in the array, and an inner loop that iterates over the unsorted elements. Within the inner loop, we compare adjacent elements and swap them if they're in the wrong order. We repeat this process until the array is sorted.

However, as mentioned earlier, bubble sort has a time complexity of O(n^2), which makes it inefficient for larger data sets. There are other sorting algorithms such as merge sort or quicksort with a lower time complexity that are more suitable for large data sets.

Node.js is an open-source, cross-platform runtime environment that allows developers to run JavaScript code outside of a web browser.

Some of the features of Node.js include:

• Asynchronous and event-driven: It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, making it ideal for building scalable network applications.
• Fast: Being built on top of Google's V8 JavaScript engine, Node.js is very fast in code execution.
• Single-threaded: Node.js uses a single-threaded model with event looping which enables it to handle a large amount of incoming connections, making it highly scalable.
• Large module library: Node.js has a large library of modules written by other developers that can be easily integrated into your project.

Node.js works by running JavaScript code outside of the web browser environment, instead using the V8 JavaScript engine to execute the code. It reads the JavaScript file, executes the code, and returns the result.

Here's an example of a basic HTTP server in Node.js:

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const http = require('http');

const hostname = '127.0.0.1';
const port = 3000;

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello, world!');
});

server.listen(port, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`);
});

This code creates an HTTP server that listens for incoming requests on port 3000. When a request is received, it responds with a plain text message of "Hello, world!".

You can learn more about Node.js on their official website: https://nodejs.org/en/about/

GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. It provides an efficient, powerful and flexible approach to developing web APIs. It was initially released by Facebook in 2015 and has gained popularity due to its performance, clear documentation, and good error handling. GraphQL enables declarative data fetching where the client can specify exactly what data it needs from an API. It's used to build client applications that require seamless data retrieval from multiple sources. More information can be found at graphql.org.