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.
Which command is used to install a Node.js package globally?
- npm global install
- npm i -g
- npm install -g
- npm add -g
To install a Node.js package globally, you should use the npm install -g command. This makes the package available for use across different projects. The other options may not work as expected or are not the recommended way to install packages globally.
When implementing indexing, what factors should be considered to mitigate the impact on database write performance?
- Selective indexing
- Index maintenance strategy
- Using index-only scans
- Increasing index size
When implementing indexing, factors to consider for mitigating the impact on write performance include selective indexing (indexing only the columns that are frequently queried), choosing an appropriate index maintenance strategy (e.g., periodic maintenance rather than immediate updates), and using index-only scans to reduce disk I/O during reads. Increasing the index size can have a negative impact on write performance, so it should be done judiciously.
In Node.js, how can data be written to a writable stream?
- Using the read() method
- Using the write() method
- Using the pipe() method
- Using the readable() method
Data can be written to a writable stream in Node.js using the write() method. This method allows you to write data to the stream, which can be a file, network connection, or any other writable destination. The pipe() method is used for piping data from a readable stream to a writable stream, and the other options are not the correct ways to write data to a writable stream.