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20 Advanced Golang Interview Questions asked for a Senior Developer position

I have taken many interviews and these are some of the questions I ask consistently to test a candidate's knowledge on go

What are goroutines and how are they different from threads?

Goroutines are lightweight threads managed by the Go runtime.
They are cheaper to create and have lower memory overhead compared to traditional operating system threads.

How do you handle panics and recover from them in Go?

Panics are unexpected errors that can occur during program execution. 

You can use the recover() function inside a deferred function to catch and handle panics.

What is the difference between defer, go, and goroutine?

defer is used to schedule a function call to be executed when the surrounding function returns.
go is used to start a new goroutine for concurrent execution. goroutine is the lightweight thread managed by the Go runtime.

How do you handle concurrent access to shared data in Go?

You can use synchronization primitives like mutexes, channels, or the sync package to handle concurrent access to shared data and prevent race conditions.

What are closures in Go?

Closures are functions that capture and use variables from their surrounding lexical scope.

They are often used in Go to create anonymous functions.

How do you handle errors in Go? What are some best practices?

Go encourages explicit error handling. You can use multiple return values to return errors along with results.
It is recommended to handle errors explicitly and avoid ignoring them.

What are the differences between value receivers and pointer receivers in Go methods?

Value receivers receive a copy of the value, while pointer receivers receive a pointer to the value.

Pointer receivers can modify the value they receive, while value receivers cannot.

How do you implement interfaces in Go?

Interfaces in Go are implemented implicitly. If a type satisfies all the methods of an interface, it is said to implement that interface.

There is no need to explicitly declare that a type implements an interface.

What are channels in Go and how are they used for communication between goroutines?

Channels are a core concurrency primitive in Go. They provide a way for goroutines to communicate and synchronize their execution.

Data can be sent and received through channels using the <- operator.

What is the purpose of the context package in Go?

The context package provides a way to pass cancellation signals, deadlines, and other request-scoped values across API boundaries.

It is used to manage the lifecycle of operations and facilitate cancellation and timeout handling.

How do you handle dependencies in Go?

Go encourages the use of dependency injection to handle dependencies. Dependencies should be passed as parameters to functions or struct methods instead of being directly instantiated or accessed.

What is the purpose of the init() function in Go?

The init() function is a special function in Go that is automatically called before the program starts.

It is often used for initialization tasks such as registering drivers, initializing global variables, or setting up configuration.

What are defer statements and how are they useful?

Defer statements are used to schedule a function call to be executed when the surrounding function returns.
They are commonly used to ensure cleanup tasks are performed, such as closing files or releasing resources.

How do you write concurrent tests in Go?

Go provides the testing package, which includes support for running tests concurrently. By default, tests are run sequentially, but you can use the -parallel flag to run tests concurrently.

Can you explain the concept of garbage collection in Go?

Go has a built-in garbage collector that automatically manages memory allocation and deallocation.

It tracks objects that are no longer referenced and frees up memory occupied by those objects.

What is the purpose of the sync package in Go?

The sync package provides synchronization primitives like mutexes, condition variables, and wait groups.

It is used for managing shared access to data and coordinating the execution of goroutines.

How do you handle time-related operations in Go?

Go provides the time package for working with dates, times, durations, and timers.

It offers functions and methods for parsing, formatting, and manipulating time values.

What is the difference between shallow copy and deep copy in Go?

Shallow copy creates a new variable that points to the same underlying data, while deep copy creates a new variable with its own separate copy of the data. The copy() function can be used for shallow copying slices.

How do you handle file I/O operations in Go?

Go provides the os and io packages for file I/O operations.
You can open files, read from and write to them, and perform other file-related operations using the functions and methods provided by these packages.

Can you explain how to write concurrent programs using channels and goroutines?

To write concurrent programs, you can create goroutines to perform tasks concurrently.

Communication and synchronization between goroutines can be achieved using channels, where data can be passed between goroutines.

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Top comments (1)

davidkroell profile image
David Kröll

The copy() function can be used for shallow copying slices.

Doesn't the copy() create deep copies?