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.
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.
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.
What happens to the prototype chain when using Object.create(null) in JavaScript?
- It creates an empty object with no prototype
- It inherits from the Object prototype
- It inherits from the null prototype
- It creates an object with its own prototype chain
Using Object.create(null) in JavaScript creates an empty object with no prototype, effectively removing it from the prototype chain. This is useful in scenarios where you want to create objects without inheriting any properties or methods from the default Object prototype.
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.