Connection to a NoSQL database like MongoDB in Node.js usually returns a ______ object.
- MongoClient
- Promise
- HttpServer
- Buffer
When connecting to a NoSQL database like MongoDB in Node.js, you typically get a MongoClient object. This object represents the database connection and allows you to perform various database operations. The other options are not related to MongoDB connections.
Which method should be used to handle the rejection of a Promise?
- reject()
- catch()
- error()
- failure()
To handle the rejection of a Promise, you should use the catch() method. It allows you to specify what to do when the Promise is rejected with an error. The other options are not standard methods for handling Promise rejection in JavaScript.
In the context of security, what does the principle of "least privilege" mean?
- Giving users the fewest privileges necessary to perform their tasks
- Giving users all possible privileges
- Giving administrators fewer privileges than regular users
- Giving privileges based on user seniority
The principle of "least privilege" means giving users the fewest privileges necessary to perform their tasks. This reduces the risk of unauthorized access and potential security breaches. The other options do not align with this security principle.
When connecting to a SQL database in Node.js, the ______ method is commonly used to execute SQL queries.
- query()
- execSQL()
- runQuery()
- execute()
When connecting to a SQL database in Node.js, the query() method is commonly used to execute SQL queries. This method is provided by most SQL database libraries for Node.js and allows you to send SQL queries to the database. Options 2, 3, and 4 are not standard methods for executing SQL queries in Node.js.
How can you implement inheritance between two objects in JavaScript?
- Prototypal Inheritance
- Object Composition
- Class Inheritance
- Functional Inheritance
In JavaScript, inheritance can be implemented through Prototypal Inheritance. Objects can inherit properties and methods from other objects by setting their prototype. The other options describe alternative approaches to code reuse and object creation but don't involve direct inheritance.
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.