NodeJS Interview Questions asked to me with answers.

Question: Can you provide an overview of your experience with Node.js? Answer: I have been working with Node.js for the past [X] years, primarily building server-side applications and REST APIs. I am familiar with the core features and functionality of Node.js, as well as various libraries and frameworks commonly used in the ecosystem, such as Express, Socket.io, and NestJS.

Question: Can you explain the concept of middleware in Node.js? Answer: Middleware refers to functions that have access to the request and response objects in an Express application. These functions can be used to modify incoming requests or generate responses before they are sent to the route handlers. Middleware can be used to perform tasks such as parsing request bodies, authenticating requests, and adding CORS headers.

Question: Can you describe the concept of a pipeline in Node.js? Answer: A pipeline in Node.js refers to a series of processes connected in such a way that the output of one process is the input of the next. This allows for the efficient handling and processing of data streams, such as reading data from a file and then immediately writing it to another file or sending it over a network connection.

Question: Can you explain the purpose of the Buffer class in Node.js? Answer: The Buffer class in Node.js is a global class that allows the manipulation of binary data. It is useful for storing data that needs to be written to a stream, such as a file or network connection, or for performing low-level manipulation of binary data.

Question: Can you explain the purpose of the module.exports object in Node.js? Answer: The module.exports object in Node.js is used to define the values that a module exports for use in other modules. When a module is imported using the require function, the value of module.exports is returned to the calling module. This can be used to export functions, objects, or primitive values from a module.

Question: How can we access the resolved value of a promise in Node.js if one of the functions within the promise chain throws an error?

Answer: If one of the functions within the promise chain throws an error, the promise will be rejected and we can catch the error using the catch method. The catch method takes a single argument, which is a function that will be called with the rejected value. We can then access the resolved value of the promise by returning it within the catch function. For example:

promise
  .then(function(value) {
    // ...
  })
  .catch(function(error) {
    // Access the resolved value of the promise here
    return error;
  });