When destructuring arrays, using the rest operator will result in a new array containing the ______ elements.
- First
- Last
- Middle
- Remaining
When destructuring arrays using the rest operator, it will result in a new array containing the "Remaining" elements. The rest operator collects the remaining elements of an array into a new array.
What is the difference between process.nextTick() and setImmediate() in Node.js?
- process.nextTick() executes callbacks before any I/O events. setImmediate() executes callbacks after I/O events.
- process.nextTick() is used for synchronous execution, while setImmediate() is used for asynchronous execution.
- process.nextTick() is a browser API, and setImmediate() is a Node.js API.
- process.nextTick() has a higher priority than setImmediate().
The primary difference between process.nextTick() and setImmediate() in Node.js is their timing. process.nextTick() executes callbacks before any I/O events, allowing you to schedule code to run immediately after the current operation, while setImmediate() executes callbacks after the current I/O event loop phase, providing a smoother event loop. The other options do not accurately describe the difference.
You are designing a real-time data processing system where data needs to be transformed before being sent to another service. How would you implement streams in Node.js to ensure smooth data transformation and transmission?
- Use a single function to transform data and send it directly to the service.
- Implement a Readable stream to receive data, transform it with a Transform stream, and then pipe it to a Writable stream that sends it to the service.
- Store all incoming data in memory, transform it, and then send it to the service.
- Use asynchronous callbacks to process data and send it to the service as it arrives.
In a real-time data processing system, you should implement streams. Use a Readable stream to receive data, transform it with a Transform stream, and then pipe it to a Writable stream that sends it to the service. This approach allows for smooth data transformation and transmission without storing large amounts of data in memory.
Which fs method would you use to read the contents of a directory?
- fs.readdir()
- fs.read()
- fs.readDir()
- fs.listDirectory()
To read the contents of a directory in Node.js, you should use the fs.readdir() method. It returns an array of all the file and directory names in the specified directory. The other options are not valid fs methods for this purpose.
You are designing a database schema for an e-commerce application, focusing on optimal performance. How would you design the schema and optimize queries to minimize the load on the database?
- Use a denormalized schema
- Implement proper indexing
- Utilize stored procedures for all queries
- Avoid using primary keys
To minimize the load on the database in an e-commerce application, implementing proper indexing is crucial. Indexes allow the database to efficiently retrieve data. Denormalized schemas can lead to redundancy and maintenance challenges. While stored procedures can be useful, they are not the primary means of optimizing queries. Avoiding primary keys is not recommended; they are essential for data integrity.
Which of the following accurately describes Non-Blocking I/O in Node.js?
- I/O operations that block the main thread
- I/O operations that execute concurrently
- I/O operations that are not supported in Node.js
- I/O operations that must be executed in a callback
Non-Blocking I/O in Node.js refers to I/O operations that execute concurrently without blocking the main thread. It allows Node.js to perform multiple I/O operations without waiting for each operation to complete. The other options describe blocking I/O or do not accurately describe non-blocking I/O.
What is the primary advantage of using connection pooling when interacting with a database?
- Improved Performance
- Enhanced Security
- Simplified Query Language
- Reduced Data Redundancy
Connection pooling improves performance. It allows reusing established database connections, reducing the overhead of creating and closing connections for every database operation. This results in faster response times and efficient resource usage.
How can specific error handlers be created to respond to different error types in Express.js?
- Use the try...catch block
- Define multiple catch blocks
- Use the app.error() middleware
- Utilize the next(err) function with custom error classes
In Express.js, specific error handlers for different error types can be created by utilizing the next(err) function with custom error classes. This allows you to define error-handling middleware that can respond to specific error types based on their custom classes. The other options are not typically used for handling specific error types in Express.js.
You are developing a user management system and need to design routes for CRUD operations. How would you structure the routes to follow RESTful principles in Express.js?
- Use any route structure that suits your needs
- Design routes like /createUser, /getUser, /updateUser, /deleteUser
- Structure routes as /users, using HTTP methods (GET, POST, PUT, DELETE) to indicate CRUD operations
- Create routes like /addUser, /fetchUser, /modifyUser, /removeUser
To follow RESTful principles in Express.js, you should structure routes as a resource, such as /users, and use HTTP methods (GET, POST, PUT, DELETE) to indicate CRUD operations on that resource. This approach aligns with RESTful conventions, making your API more intuitive and standardized. Option 2 doesn't follow RESTful principles, and Options 1 and 4 lack the structured approach recommended for RESTful APIs.
To parse URL-encoded data, Express uses the ______ middleware.
- body-parser
- express-parser
- data-parser
- url-parser
Express uses the body-parser middleware to parse URL-encoded data in incoming requests. This middleware is essential for handling form submissions and other data sent in the request body.