Go (Golang) Guide: Top 30 Interview Questions & Answers
Go (Golang) is a statically typed, compiled programming language developed by Google. Known for its simplicity, concurrency support, and fast execution, Go is widely used in cloud-native development, microservices, and system programming. This guide provides 30 top Go interview questions with detailed explanations and code examples for beginners and experienced developers.
1. What is Go (Golang)?
Explanation:
Go is an open-source programming language designed for simplicity, performance, and concurrency. It supports garbage collection, strong typing, and built-in concurrency with goroutines.
Example:
2. Difference between Go and other languages like Java or C++
Feature | Go | Java/C++ |
---|---|---|
Compilation | Compiled to machine code | Java: bytecode, C++: native |
Concurrency | Goroutines & channels | Threads, Executor services |
Memory management | Garbage-collected | Manual or GC (Java) |
Simplicity | Minimalistic | Complex syntax |
3. What are Goroutines?
Explanation:
Goroutines are lightweight threads managed by the Go runtime. They are used for concurrent programming.
Example:
4. What are Channels in Go?
Channels are used to communicate between goroutines safely.
Example:
5. Difference between buffered and unbuffered channels
Channel Type | Behavior |
---|---|
Unbuffered | Send blocks until receiver receives |
Buffered | Send does not block until buffer full |
Example:
6. What is a Go Module?
Explanation:
Go modules manage dependencies and versions in Go projects.
Example:
7. How to handle errors in Go
Go does not use exceptions; instead, it returns errors as values.
Example:
8. What is the difference between :=
and var
in Go?
-
:=
– short variable declaration, infers type -
var
– explicit declaration, optional initialization
9. What are Structs in Go?
Structs are used to group related fields together.
Example:
10. What are Interfaces in Go?
Interfaces define method sets that a type must implement.
Example:
11. Difference between Array and Slice
Feature | Array | Slice |
---|---|---|
Size | Fixed | Dynamic |
Declaration | var arr [3]int | arr := []int{1,2,3} |
12. What are Maps in Go?
Maps are key-value pairs, similar to dictionaries in Python.
Example:
13. How to use Go’s defer
keyword?
Defer postpones execution of a function until surrounding function returns.
Example:
14. Explain go fmt
go fmt
formats Go code according to standard conventions. It ensures consistency across projects.
15. How to use Go’s select
statement?
select
is used to wait on multiple channel operations.
Example:
16. What is panic
and recover
?
-
panic
stops normal execution and begins unwinding stack -
recover
stops a panic inside a deferred function
17. How to implement concurrency safely?
-
Use goroutines for parallelism
-
Use channels or sync package to avoid race conditions
18. What are Go Packages?
Packages organize related functions, types, and interfaces.
19. How to run tests in Go
Use Go’s built-in testing package:
Run:
20. What is the difference between new
and make
?
Function | Usage |
---|---|
new | Allocates memory, returns pointer |
make | Initializes slices, maps, channels |
21. How to handle JSON in Go
Example:
22. Difference between copy
and append
-
copy
– copies elements from one slice to another -
append
– adds elements to a slice
23. What are Pointers in Go?
Pointers store the memory address of a variable.
24. Explain iota
in Go
iota
is used for enumeration constants.
25. What is Go’s init()
function?
init()
executes before main() and is used for setup.
26. How to handle time and date in Go
27. Explain Go Interfaces vs Abstract Classes
-
Go interfaces only define methods; no fields
-
Go does not have abstract classes; interfaces + composition are used instead
28. How to implement REST API in Go
Using Gin framework:
29. Difference between Go routines and Threads
Feature | Goroutine | Thread |
---|---|---|
Memory | Low (~2KB) | High (~1MB) |
Scheduling | Managed by Go runtime | OS managed |
Creation | Cheap | Expensive |
30. How to handle environment variables
✍️ By Ashish | 2025-10-21T09:00:56.147Z