You're in an interview, and the interviewer asks,

How many types of API functions are available in Node.js? Explain them.

here's how you can answer:

Sample Answer:

In Node.js, there are mainly two types of API functions: blocking (synchronous) and non-blocking (asynchronous).

Blocking functions execute code one line at a time, meaning the next line won’t run until the current task is finished. For example, when you use fs.readFileSync() to read a file, it waits until the file is completely read before moving on to the next line of code. This approach can slow down the application if the task takes a long time because it blocks everything else from running.

Non-blocking functions, on the other hand, let other code run while the task is happening in the background. For instance, fs.readFile() reads a file asynchronously and immediately moves on to the next line without waiting. This makes non-blocking functions much faster and more efficient, especially for tasks like reading files, making network requests, or interacting with a database.

Node.js relies heavily on non-blocking functions because they help the application handle many tasks at once without getting stuck, making it more responsive and scalable. This approach is great for high-performance applications like web servers, where you need to handle multiple requests at the same time without delays.

So, to sum it up: blocking functions execute tasks one by one, stopping other code from running, while non-blocking functions run tasks in the background, keeping everything else running smoothly.

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