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 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.
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.
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 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.
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.
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.
To optimize the serving of static files in Express.js, enabling caching is a common practice.
- Compression
- Minification
- Preloading
- Caching
Enabling caching is a common practice in Express.js to optimize the serving of static files. Caching allows the server to store and reuse static files, reducing the need to fetch them from the disk or generate them on each request, thus improving performance.
You are tasked with creating an HTTP proxy server using the http module. What steps and considerations would you take to handle incoming requests and forward them to the appropriate destination?
- Parse the incoming request, extract the destination URL, and create a new request to the destination server.
- Directly pass the incoming request to the destination server without any parsing.
- Block all incoming requests as proxy servers should only send responses.
- Use the 'fs' module to read and forward the request to the destination.
To create an HTTP proxy server, you should parse the incoming request, extract the destination URL, and create a new request to the destination server. The other options are not suitable for proxy server implementations.
To specify a specific version of a package in the package.json file, you can use a ______ to define the exact version number.
- semver
- specifier
- version-lock
- exact
To specify a specific version of a package in the package.json file, you can use a semver specifier to define the exact version number or a range of versions you want to use. Semver specifiers allow for flexibility in specifying version requirements for packages.
In a content delivery network (CDN), the process of distributing copies of files to multiple geographically dispersed servers is known as ______.
- Load Balancing
- Replication
- Caching
- Clustering
In a content delivery network (CDN), the process of distributing copies of files to multiple geographically dispersed servers is known as "Replication." This ensures that content is readily available to users from nearby servers, reducing latency and improving load times. Load balancing, caching, and clustering are related concepts but not specific to CDN replication.
Which caching strategy involves keeping the most recently used items?
- LRU (Least Recently Used)
- FIFO (First In, First Out)
- Random Replacement
- LFU (Least Frequently Used)
The caching strategy that involves keeping the most recently used items is called LRU, which stands for "Least Recently Used." In LRU caching, when the cache is full and needs to make space for a new item, it removes the least recently accessed item. This strategy is often used to maximize cache efficiency.