How can you ensure that a specific version of npm is used in your Node.js project?
- By defining the npm version in the package.json file.
- By modifying the NODE_PATH environment variable.
- By running the 'npm use' command.
- By using a package manager like Yarn instead of npm.
You can ensure a specific version of npm is used in your Node.js project by defining the desired npm version in the engines field of your project's package.json file. This helps maintain consistency and ensures that others working on the project use the correct npm version.
You are developing a RESTful API using the http module and need to support CORS. How would you implement CORS headers to handle pre-flight requests in your HTTP server?
- Access-Control-Allow-Origin: *
- Access-Control-Allow-Origin: mydomain.com
- Access-Control-Allow-Origin: true
- Access-Control-Allow-Origin: false
To support CORS in your HTTP server, you should set the Access-Control-Allow-Origin header to the specific domain (e.g., mydomain.com) from which you want to allow requests. Using a wildcard (*) is less secure as it allows any domain, and using true or false is not the correct syntax for this header.
You are developing a media hosting platform where users can upload images and videos. How would you design the file storage and retrieval system to ensure high availability and low latency for users across the globe?
- Use a content delivery network (CDN) to cache and distribute media files to edge servers around the world.
- Store all media files on a single, centralized server to simplify management.
- Use a local file storage system for each region separately.
- Implement a peer-to-peer (P2P) system for users to share media directly.
To ensure high availability and low latency, using a CDN is the recommended approach. CDNs cache content on edge servers located across the globe, reducing the distance between users and the data they request. The other options may lead to latency issues and lower availability.
A common practice for improving error handling in Express.js is to centralize error handling using a ______.
- try-catch block
- catchError middleware
- globalErrorHandler middleware
- throw statement
A common practice for improving error handling in Express.js is to centralize error handling using a globalErrorHandler middleware. This middleware is responsible for handling errors that occur during request processing. While try-catch blocks can be used within routes, they don't centralize error handling, and catchError and throw are not standard middleware constructs in Express.js.
You are tasked with developing a system to read and process large files without consuming a lot of memory. How would you utilize streams in Node.js to efficiently read, process, and write the data?
- Use a Readable stream to read the file in chunks, process data asynchronously, and then write to a Writable stream.
- Read the entire file into memory, process it, and then write it back to disk.
- Use a synchronous file reading approach to minimize memory usage.
- Use a single callback function to read and process the entire file sequentially.
To efficiently process large files, you should use a Readable stream to read the file in chunks, process data asynchronously, and then write to a Writable stream. This approach minimizes memory usage and is ideal for handling large files in Node.js.
What is the significance of implementing Multi-Factor Authentication (MFA) in web applications?
- MFA adds an extra layer of security by requiring users to provide multiple forms of authentication, such as a password and a fingerprint scan.
- MFA simplifies the authentication process by reducing the number of login attempts.
- MFA is primarily used for tracking user behavior and analytics.
- MFA is only useful for protecting against physical security threats.
Implementing Multi-Factor Authentication (MFA) is significant in web applications as it adds an extra layer of security by requiring users to provide multiple forms of authentication, making it harder for unauthorized users to gain access even if they have the user's password. MFA enhances security and helps protect user accounts from various online threats.
In Express.js, to skip the remaining route callbacks and pass control to the next middleware function, you can call the ______ function.
- next()
- skip()
- pass()
- continue()
In Express.js, the next() function is used to skip the remaining route callbacks within a middleware function and pass control to the next middleware function in the chain. The other options are not valid functions for this purpose.
What type of object is passed as the first argument to the request listener function when creating an HTTP server?
- request
- response
- server
- http
The first argument passed to the request listener function when creating an HTTP server is the request object. This object contains information about the incoming HTTP request, such as headers, URL, and HTTP method. It allows you to read and process client requests.
When designing schemas for large-scale systems, the principle of ________ involves dividing the dataset into smaller, more manageable parts.
- Sharding
- Normalization
- Aggregation
- Indexing
The principle of "sharding" involves dividing the dataset into smaller, more manageable parts, typically based on a certain criteria like range or hash, to distribute data across multiple servers or nodes in a distributed system. Sharding is a crucial concept in achieving horizontal scalability in databases.
When configuring the static files directory in Express.js, the path specified is relative to the ______ directory.
- current
- project
- root
- parent
When configuring the static files directory in Express.js, the path specified is relative to the root directory of your project. This means that you specify the path from the root of your project's directory structure.