Node.js Interview Questions and Answer set 2

Categories: Interview questions and answers Freshers Node JS

Node.js Interview Questions and Answer for freshers (set 2)

Q1. What is the control flow function?

Answer: The control flow function is a common code snippet, which executes whenever there are any asynchronous function calls made, and they are used to evaluate the order in which these functions are executed in Node.js.

Q2. Why is Node.js so popular these days?

Answer: Node.js has gained an immense amount of traction as it mainly uses JavaScript. It provides programmers with the following options:

• Writing JavaScript on the server
• Access to the HTTP stack
• File I/O entities
• TCP and other protocols
• Direct database access

Q3. What is an event loop in Node.js?

Answer: When running an application, callbacks are entities that have to be handled. In the case of Node.js, event loops are used for this purpose. Since Node.js supports the non-blocking send, this is a very important feature to have.

The working of an event loop begins with the occurrence of a callback wherever an event begins. This is usually run by a specific listener. Node.js will keep executing the code after the functions have been called, without expecting the output prior to the beginning.

Once, all of the code is executed, outputs are obtained and the callback function is executed. This works in the form of a continuous loop, hence the name event loop.

Q4. What are the asynchronous tasks that should occur in an event loop?

Answer: Following are some of the tasks that can be done using an event loop asynchronously:

• Blocking send requests
• High computational requirement
• Real-time I/O operations

Q5. What is the order of execution in control flow statements?

Answer: The following is the order in which control flow statements are used to process function calls:

• Handling execution and queue
• Data collection and storage
• Concurrency handling and limiting
• Execution of the next piece of code

Q6. What are the input arguments for an asynchronous queue?

Answer: There are two main arguments that an asynchronous queue uses. They are:

• Concurrency value
• Task function

Q7. Are there any disadvantages to using Node.js?

Answer: A multi-threaded platform can run more effectively and provide better responsiveness when it comes to the execution of intensive CPU computation, and the usage of relational databases with Node.js is becoming obsolete already.

Q8. What is the primary reason to use the event-based model in Node.js?

Answer: The event-based model in Node.js is used to overcome the problems that occur when using blocking operations in the I/O channel.

Next in this blog comprising Node.js questions, you need to understand how you can import libraries into Node.js.

Q9. How can you import external libraries into Node.js?

Answer: External libraries can be easily imported into Node.js using the following command:

var http=require (“http”)

This command will ensure that the HTTP library is loaded completely, along with the exported object.

Q10. What is meant by event-driven programming in Node.js?

Answer: Event-driven programming is a technique in which the workflow execution of a program is mainly controlled by the occurrence of events from external programs or other sources.

The event-driven architecture consists of two entities, namely:

• Event handling
• Event selection