Which grant type in OAuth 2.0 is suitable for machine-to-machine applications where a user is not involved?
- Client Credentials
- Authorization Code
- Implicit
- Resource Owner Password Credentials
The Client Credentials grant type in OAuth 2.0 is suitable for machine-to-machine (M2M) applications where there is no user involved. It allows an application to directly authenticate itself and obtain an access token. The other grant types involve user interaction and are not intended for M2M scenarios.
How can you determine the type of a variable in JavaScript?
- typeOf(variable)
- get.type(variable)
- variable->type
- typeof variable
In JavaScript, the typeof operator can be used to determine the type of a variable. The syntax is typeof variableName. The other options are not valid methods to determine the type in JavaScript.
You are assigned to optimize a Node.js application that is experiencing performance bottlenecks. The application heavily relies on reading and writing data to the file system. Which approach would be most effective in optimizing file system-related operations?
- Use asynchronous file system operations
- Increase CPU resources
- Optimize database queries
- Minimize network requests
In Node.js, using asynchronous file system operations (such as fs.readFile and fs.writeFile) is the most effective way to optimize file system-related operations. This prevents blocking the event loop and ensures that your application remains responsive while reading and writing files.
What considerations should be made when implementing full-text search to ensure relevance and accuracy of search results?
- Stemming and lemmatization
- Exact matching
- Case sensitivity
- Shortening query length
When implementing full-text search, considerations should include stemming and lemmatization to handle variations of words (e.g., "run," "running," "ran"). This ensures that search results are more comprehensive and relevant. Exact matching alone may miss variations. Case sensitivity should be considered based on user requirements. Shortening query length may lead to the exclusion of important search terms.
In a Cache-Aside strategy, when is the data loaded into the cache?
- Data is loaded into the cache on write operations.
- Data is loaded into the cache on read operations.
- Data is automatically loaded when the cache is initialized.
- Data is loaded into the cache periodically on a fixed schedule.
In a Cache-Aside strategy, data is not automatically loaded into the cache. Instead, it's loaded explicitly on read operations when an application requests the data.
How does the use of mocking and stubbing affect the isolation of unit tests?
- It increases isolation by replacing real dependencies with controlled substitutes.
- It reduces isolation by relying on actual dependencies.
- It has no effect on isolation.
- It increases isolation by running tests concurrently.
The use of mocking and stubbing in unit tests increases isolation by replacing real dependencies, such as external services or APIs, with controlled substitutes. This allows you to focus on testing the specific unit of code without worrying about the behavior of the real dependencies. Option (2) is incorrect because relying on actual dependencies doesn't create isolation in unit tests. Options (3) and (4) are also incorrect.
How can middleware be added to an Express application to process requests?
- Using the use() method
- Using the get() method
- Using the addMiddleware() function
- Using the handleRequest() method
Middleware can be added to an Express application using the use() method. This method allows you to specify middleware functions that can process requests in the order they are defined. The other options are not standard ways of adding middleware in Express.
What happens to the Event Loop when the callback queue and the task queue are both not empty?
- It suspends the Event Loop until both queues are empty.
- It processes callbacks from the callback queue before tasks from the task queue.
- It processes tasks from the task queue before callbacks from the callback queue.
- It randomly selects items to process from both queues.
When both the callback queue and the task queue are not empty, the Event Loop in Node.js follows a specific order. It first processes callbacks from the callback queue before moving to tasks from the task queue. This order ensures that callback functions, which often include I/O operations, are handled promptly.
Which of the following array methods does not mutate the original array in JavaScript?
- splice()
- push()
- concat()
- pop()
The concat() method in JavaScript creates a new array that combines the elements of the original array and the elements passed as arguments, without modifying the original array. The other methods, such as splice(), push(), and pop(), directly modify the original array.
The fs.createReadStream method is particularly useful when dealing with ______ sized files.
- small
- large
- binary
- text
The fs.createReadStream method in Node.js is particularly useful when dealing with large sized files. This method allows you to efficiently read large files in smaller chunks, which can be memory-efficient for handling large datasets.