The _______ data type in Go is used to represent a sequence of bytes.
- array
- bytes.Buffer
- slice
- string
In Go, the _______ data type is represented by the string type. A string is a sequence of bytes, commonly used for representing text data. It is immutable and UTF-8 encoded, allowing for efficient handling of text in various languages.
The '_____' operator in Go is used to perform bit clear (AND NOT).
- &
- &^
- <
- ^
The correct operator to perform bit clear (AND NOT) in Go is the '&' operator followed by the '^' symbol, forming '&^'. This operator clears bits in the first operand based on the corresponding bits in the second operand.
Go interfaces promote _______ programming by allowing objects to interact without knowing their concrete types.
- Dynamic
- Generic
- Polymorphic
- Static
Polymorphic programming is promoted by Go interfaces, enabling different types to be treated uniformly through shared interfaces. This encourages code reuse, flexibility, and adaptability by allowing functions and methods to accept a wide range of types as arguments without the need for explicit type declarations.
The _______ method in the database/sql package is used to execute a SQL query that returns rows.
- Exec
- Query
- Prepare
- Close
The correct option is Query. The Query method in database/sql package is used to execute a SQL query that returns rows. This method is used when you expect rows to be returned from the query execution.
A method with a _______ receiver in Go can modify the fields of the receiver struct.
- Function
- Interface
- Pointer
- Value
In Go, methods with pointer receivers can modify the fields of the receiver struct, while methods with value receivers cannot. This is because methods with pointer receivers operate on the actual instance of the struct rather than a copy.
Suppose you're designing a system where multiple goroutines need to communicate with each other asynchronously. Which concurrency construct in Go would you use and why?
- Use a sync.Mutex to achieve mutual exclusion
- Use atomic operations for shared memory access
- Use channels due to their simplicity, safety, and built-in synchronization
- Use semaphores for resource synchronization
Channels are a preferred choice for inter-goroutine communication in Go due to their safety features and built-in synchronization, simplifying the development process.
What is the purpose of using the 'testing' package's 't.Parallel()' method in Go tests?
- Allows parallel execution of tests
- Ensures sequential execution of tests
- Provides debugging information
- Skips the test execution
In Go, the 't.Parallel()' method in the 'testing' package is used to allow parallel execution of tests. When a test function calls 't.Parallel()', it informs the testing framework that this test can be run in parallel with other tests. This can help in speeding up the test execution time, especially when dealing with I/O-bound or CPU-bound tests. It's essential to ensure that the test functions are safe for parallel execution to avoid race conditions or other concurrency issues.
The _______ keyword in Go is used to declare anonymous functions.
- func
- defer
- go
- anonymous
In Go, anonymous functions are declared using the func keyword followed by an optional parameter list and return type. Thus, the correct option is 'anonymous'.
Suppose you're building an e-commerce platform in Go, and you need to implement rate limiting to prevent abuse of your API endpoints. How would you design and implement middleware for this purpose?
- Develop middleware that tracks the number of requests from each client IP address and denies access if the limit is exceeded.
- Implement a distributed caching mechanism to store and manage rate-limiting data across multiple instances.
- Use built-in rate-limiting features provided by cloud service providers like AWS or Google Cloud.
- Utilize a centralized rate-limiting service that communicates with each microservice to enforce limits.
Middleware designed for rate limiting intercepts incoming requests, checks the request rate against predefined thresholds, and either allows or denies access accordingly. In this case, tracking the number of requests from each client IP address enables you to enforce rate limits effectively. Utilizing a centralized rate-limiting service introduces additional network overhead and potential single points of failure, complicating the architecture. While cloud service providers offer rate-limiting features, they may not be as flexible or customizable as implementing middleware tailored to your application's specific requirements. Implementing a distributed caching mechanism adds unnecessary complexity and overhead, making it less suitable for this purpose.
The _______ package in Go provides support for hashing and encryption functions commonly used in authentication.
- crypto
- encoding
- net
- fmt
The correct option is crypto. The crypto package in Go provides implementations for various cryptographic functions, including hashing and encryption, which are essential for authentication systems.