How do you access the session in JWT if the user send a request to the server1 and the session is stored in the server1 and after when a request send to the server2?

- **JWT (JSON Web Token)**:
  - JWTs are stateless tokens that carry information in a compact and self-contained manner.
  - They are commonly used for authentication and information exchange between parties.
- **Session in JWT**:
  - Since JWTs are stateless, they do not rely on server-side sessions.
  - When a user sends a request to Server1 and the session is stored there, Server1 creates a JWT containing the necessary session data and sends it back to the client.
  - The client then includes this JWT in subsequent requests to Server2.
- **Accessing Session in JWT Across Servers**:
  - Server2 validates and decodes the JWT using its secret key to extract the session data.
  - This allows Server2 to access the session information without the need for direct communication with Server1.
- **Key Points**:
  - JWTs enable cross-server session access by securely encoding session data within tokens.
  - Each server must share a common secret key to validate and decode JWTs.


Event Loop in nodejs?
Event Loop:
The event loop is a core concept in Node.js that enables non-blocking I/O operations.
It manages asynchronous operations and callbacks efficiently, allowing Node.js to handle high concurrency.
Working of Event Loop:
It continuously checks the call stack for any synchronous operations to execute.
If the call stack is empty, it processes asynchronous tasks from the event queue.
Asynchronous tasks include I/O operations, timers, and callbacks.


Print the output of the array when the callback function of an array is given as async in javascript?

When the callback function of an array is asynchronous (async), the output of the array depends on how the async operations are handled. If the async operations are awaited inside the callback function, the array may not be fully processed before the async operations complete. Here's an example:

```javascript
const array = [1, 2, 3];

const processArrayAsync = async () => {
  await array.forEach(async (item) => {
    console.log(item);
    await new Promise(resolve => setTimeout(resolve, 1000)); // Simulating async operation
    console.log('Async operation completed for', item);
  });
  console.log('Array processing complete');
};

processArrayAsync();
```

Output:
```
1
2
3
Async operation completed for 1
Async operation completed for 2
Async operation completed for 3
Array processing complete
```

In this example, each item in the array is logged sequentially, but the async operation within the forEach loop is awaited, causing each item to be processed one by one asynchronously. The "Array processing complete" message is logged after all async operations are completed.

###
Create a route using express and pass a number through query params. Then convert the number in words code  snipet example?
Sure, here's a simple explanation in bullet points:

- **Create a Route with Express**:
  - Use Express to define a route that accepts query parameters.
  - Parse the query parameters to extract the number.
- **Convert Number to Words**:
  - Write a function to convert a number to its word representation.
  - This function can be a separate utility function or included directly in the route handler.
- **Route Handler**:
  - Define a route handler function to handle incoming requests to the specified route.
  - Extract the number from the query parameters.
  - Call the function to convert the number to words.
  - Send the converted result as a response.

Here's a code snippet example:

```javascript
const express = require('express');
const app = express();

// Route definition
app.get('/convertToWords', (req, res) => {
  const { number } = req.query;
  const words = convertToWords(Number(number));
  res.send(`Number ${number} in words: ${words}`);
});

// Utility function to convert number to words
function convertToWords(number) {
  // Logic to convert number to words
}

// Start the server
const port = 3000;
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});
```

In this example, the route `/convertToWords` accepts a query parameter named `number`. The route handler extracts the number, calls the `convertToWords` function to convert it to words, and sends the result back as a response.
######## Endpoint: /convertToWords?number=123