35+ Top Golang Interview Questions

The Go programming language, often known as Golang, is an open-source programming language that is comparable to C but is designed for speedy compilation, smooth concurrency, and developer convenience.

This language was developed and used by Google, but it has gained traction in other firms in recent years as the demand for concurrent, networked programming has grown.

Golang makes development easier for developers by offering optimal compilation for rapid software application development, smoother concurrency, enhanced runtime efficiency, and fewer defects.

Golang is quickly becoming a popular corporate programming language, with several employment options. Many IT behemoths, like Google, Uber, and Apple, adore Golang for its shorter development time, ease of learning, enhanced runtime, garbage collection, and other benefits.

As more firms use Golang, the need for Golang programmers grows. The bottom line? Learning Golang would provide several employment prospects.

If you want to work as a Golang developer, you must adequately prepare for your interview. That is why we compiled this comprehensive collection of Golang interview questions.

In this post, we will present basic to advanced Golang interview questions, so you can easily get through the interview.

1. Describe Golang.

Go is a high-level, general-purpose programming language that supports garbage collection and concurrent programming and is very tightly and statically typed. Go applications are created by utilizing packages, which provide effective dependency management.

Additionally, it makes advantage of the compile-link approach to create executable binaries from source code. Go is a straightforward language with beautiful and clear syntactic structures.

It comes with a set of strong standard libraries that can be used by developers to solve issues without the requirement for other packages.

2. What advantages does Go have over other languages?

• Go code was developed with practicality in mind, in contrast to other languages that began as intellectual experiments. Every choice in syntax and feature is made with the programmer’s convenience in mind.
• Since automatic garbage collection runs concurrently with the application, it is far more effective than Java or Python.
• Scalability and concurrency are both prioritized in Golang.
• Golang is usually considered to be more understandable than other languages since it has a single, standardized code structure.

3. In Golang programming, what is fmt?

The Format package is denoted by the symbol fmt. Users can utilize this functionality to format basic text, values, or anything else and print it.

It also allows users to receive terminal input, write to a file with a writer, and even build bespoke fancy error messages. This package is all about formatting input and output.

4. What exactly is Go Interfaces?

The interfaces in Go differ from those in other languages. Go Interfaces are a special type that is used to express a collection of one or more method signatures.

The interface is formed by using the term “type,” followed by the name and the keyword interface. The interfaces can be defined as follows:

• a collection of methods
• Type

5. What exactly are string literals?

A string literal is a string constant produced by concatenating letters. Raw and interpreted string literals are the two types of string literals. Raw string literals are enclosed by backticks (foo) and contain uninterpreted UTF-8 characters.

Interpreted string literals are strings written within double quotes and including any character except newline and incomplete double quotes.

6. How are working environments and parameters configured in Golang?

Working environments and settings can be configured using JSON, which is widely used these days. The fact that JSON is included in the standard library is its main benefit.

The standard library provides writing methods for the intended data structure, which makes it very readable. The YAML package for Go is an additional choice.

7. Describe the Golang packages?

Packages are folders that house other packages and their source code in the Go workspace. The linked packages include all of the code, including variables, functions, and types, that are written in the source files.

Every source file is a part of a package, and go packages can be stored inside packages as well.

8. What data types are supported by Golang?

Golang makes use of the following types:

• Method
• Boolean
• Numeric
• String
• Pointer
• Function
• Interface
• Slice
• Struct
• Map
• Channel
• Array

9. What do you mean by static type declaration of a variable in Golang?

The compiler can continue with another compilation without needing to have comprehensive information of the variable thanks to static type variable declarations, which reassure it that there is only one variable with the given kind and name.

A variable declaration is only important during compilation; the compiler requires a real variable and declaration when connecting to the application.

10. In Golang, what is the dynamic variable declaration?

The compiler must explain the kind of variable in a dynamic type of variable declaration based on the amount transferred to it. As a required condition, the compiler does not require a variable to categorize statically.

11. How can I utilize custom packages in the GO programming language?

If you’re creating a separate go get -table project for your library and it’s only for internal usage, you can write code like this.

• Place the library files directory under your project’s directory.
• Refer to the library by its path relative to the root of the workspace that contains the project.

12. What exactly is a goroutine? How can you put a stop to it?

A goroutine is a function or procedure that runs simultaneously with other goroutines on a dedicated goroutine thread. Goroutine threads are lighter than ordinary threads, and most Golang applications use thousands of goroutines concurrently.

A goroutine can be stopped by passing it a signal channel. Goroutines can only respond to signals if they are directed to check, therefore include checks at reasonable places like the top of your for loop.

13. Describe a rune.

In Go, a rune is a built-in type with the name int32. The Unicode CodePoint serves as the rune in Go. No matter how many bytes the codepoint takes up, it can be represented by a rune.

Runes are not required to be in order in a string. Although we can convert between string and rune, they are not the same.

14. What is the Go idiom for representing enums?

The Golang programming language doesn’t directly support enums. Iota and constants can be used to implement enums. Any of the following approaches can be used to implement an enumerated type:

• introducing a fresh integer type
• Iota is used to indicate its value.
• By providing a String function to the type

15. How does a variable’s type get checked at runtime?

The Type Switch is the most effective approach to determining a variable’s type in real-time. Variables are evaluated by type rather than value when using the Type Switch.

Both a default case, which is executed if none of the cases are true and at least one case, which serves as a conditional statement, are present in every Switch. You can, for instance, design a Type Switch that determines if the interface value i include is the type int or string:

16. Describe Go channels.

A go channel enables data transmission and transfer between goroutines. Data of the same type can be sent across one channel.

Goroutines are able to send and receive data over the same channel because of the channel’s bidirectional data flow.

17. Explain Golang Methods.

Golang does not provide classes but does support methods. These methods are identical to functions, with the exception that Go methods have a receiver parameter.

The Go method has access to the receiver’s attributes via the receiver parameters. Go methods, also known as receiver functions, aid in the presentation of a more accurate and real-world idea.

18. What exactly is a data race?

The most common and difficult debug is a data race. Unsynchronized access to shared memory or the execution of several goroutines at the same time without separate handling results in a data race fault.

19. What exactly is Go garbage collection?

Garbage collection repurposes storage that has been dynamically assigned to a program for usage by other objects. The word often refers to the waste collector’s automated regeneration for routine storage rather than explicit code (supplied by a programmer) to release particular memory blocks.

Automatic trash collection is frequently begun when the quantity of free RAM falls below a predefined threshold or after a specified number of allocations.

The elimination of items that the software no longer requires to create a place in memory for more dynamic objects is referred to as “garbage collection.”

20. Describe the stages of testing using Golang.

Golang provides automated testing of packages using custom testing suites. To establish a new suite, create a file that ends with _test.go and includes a TestXxx function, where Xxx is substituted with the name of the feature you’re testing.

A function that tests login capabilities, for example, would be named TestLogin. The testing suite file is then included in the same package as the file being tested.

The test file will be skipped during ordinary execution but will run when you input the go test command.

21. What exactly are slices in Go?

Slices are an important Go data type that provides a more powerful interface for sequences than arrays. Slices, unlike arrays, are solely typed depending on the elements they contain (not the number of elements).

To construct an empty slice with a length that is not zero, use the built-in “make” keyword.

22. What exactly is heap memory?

We store dynamically formed objects and variables in heap memory. When we no longer use an object, we usually delete the heap memory it occupied.

23. What exactly are function closures?

Function closures are a type of function value that make externally referenced variables. The function has access to and control over the referenced variables’ values.

As an illustration, the closure returned by an adder() is each tied to a different referenced sum variable.

24. What does Golang’s goto statement mean?

The goto statement functions as a jump statement in Golang. Goto is used to providing a specified label control over the program.

It can be used to skip over portions of code and go right to the necessary statements, or it can be used to repeat a portion of program code given a certain circumstance.

25. In Golang, what are Lvalue and Rvalue?

Lvalue:

• It alludes to a memory place.
• It can be changed.
• It denotes a variable identifier.
• It might occur to the left or right of the = operator.
• In the line x =20, for example, x is a lvalue and 20 is a rvalue.

Rvalue:

• It signifies a fixed value.
• It represents a memory-stored data value.
• It always occurs on the right side of the = operator.
• The expression 10 = 20 is incorrect, for example, since there is a rvalue (10) to the left of the = operator.

26. In Go, what are the looping constructs?

There is only one looping component in Go: the for loop. The for loop is made up of three parts that are separated by semicolons:

• The Init statement is run before the loop begins. It’s frequently a variable declaration that only appears within the scope of the for loop.
• Before each iteration, the condition statement is evaluated as a Boolean to decide if the loop should continue.
• The post statement is run at the conclusion of each iteration.

27. What exactly are design patterns?

Design patterns are chunks of code that can be reused to tackle common software issues. If you use design patterns, your projects will generate more modular, scalable, and efficient software. Design patterns assist you in expanding your apps and working with a team. Common design patterns include the Factory Method, Singleton, Facade, and Decorator.

28. What is the best Golang package for simple file operations? What additional Golang packages are used for file manipulation?

The platform-independent interface is provided by the os standard library package. When interacting with files, we use them for system functions. The os interface is meant to be consistent across all operating systems.

As a result, the apps we develop run the same on Windows, Linux, and Mac. Other Go standard library packages include io, ioutil, and bufio. They operate with files and add functionality. However, they are not required for fundamental file operations. We only require the os package.

29. Give an explanation of Golang’s Object-Oriented Architecture.

Golang does not use a class-object design as conventional Object-Oriented Programming does. Complex data structures and behavior are instead stored in structs and methods.

A struct is just a schema with a blueprint for the data that a structure will carry. Structures can be used to symbolize ideas from the actual world, such as books, people, or automobiles.

30. Which conversion types does Golang support?

When it comes to explicit typing, Go is highly picky. No type conversion is done automatically. To designate a variable of one type to another, type conversion must be done explicitly.

31. Describe the purpose and operation of Type assertion.

In GO, type conversion is used to transform disparate types. An explicit value of the specified type is extracted from an interface value by a type assertion.

32. What exactly is a struct type?

A struct consists of a list of named components called fields. There is a kind and a name for every field. Another way to conceive of a struct is as a group of connected properties. They are helpful for combining data to create records.

33. Explain a slice value’s backing array.

When we build a slice, Go produces a secret array called backing or underlying array behind the scenes, and the new slice type variable references to it. The items, not the slice, are stored in the backing array.

Slices are implemented in Go as data structures called slice headers, which act as the runtime representation of the slice.

34. Is it necessary to have both GOPATH and GOROOT variables, and if so, why?

Usually, neither is necessary. The only variable that has to be set to point to the Go package tree or trees is GOPATH.

GOROOT refers to the root of the home directory for the Go programming language, however, it is almost certainly already set to the location of the current Go installation.

If there are numerous Go language versions on the same system, or if the Go language was downloaded as a binary package from the internet or moved from another machine, the GOROOT variable must be set.

35. Does Golang enable inheritance?

Inheritance is a basic notion in object-oriented programming that refers to passing on the properties of the superclass to the base class.

As Golang lacks classes, inheritance is accomplished using struct embedding and structs cannot be directly expanded, we must use the idea of composition to create new objects with the struct.

36. In Golang, how does CGo appear?

From a Go source file with defined features, cGo creates Go and C files that can be concatenated into a unique Go package. C refers to a “pseudo-package,” which is a different phrase generated by cGo to refer to C’s namespace.

37. What is the pointer type in Golang?

Alphanumeric designations or labels for certain memory regions are known as variables. A type of variable known as pointer stores the memory address of another variable.

The address of a variable is represented by a pointer value, or nil if the variable has not yet been established. Just as a variable represents a value’s memory location, a pointer points to that address.

Conclusion

The goal of the Golang programming language was to create effective programs more quickly. Companies began utilizing Golang as they began to realize its advantageous possibilities.

Golang has been extremely effective in igniting the interest of developers, increasing their base use and, consequently, job opportunities. The answers to the aforementioned questions, which are the most common ones asked during Golang interviews, can help you land the Golang job you’re after.

See Hashdork’s Interview Series for help with interview preparation.