50 Best Golang Interview Questions For 2021

50 Best Golang Interview Questions For 2021

For employers and employees, the tech industry is a fast-growing, ever-changing landscape. This field is booming for developers and programmers, with a plethora of career possibilities that require a constantly expanding set of skills and knowledge. An understanding of the latest trends and skills in the field, such as Go language, or Golang, is essential for those seeking jobs in computer programming.

The purpose of this article is to explain what Golang is, to provide sample answers to several common Golang interview questions, and to provide tips for excelling at your next computer programming interview. So without further ado, let's start with the golang interview questions.

Learn or improve your Golang skills online with the best Golang tutorials for beginners.

Golang Interview Questions For Beginners and Experienced

1) What is Golang?

Golang, also known as Go Language, is a computer language developed by Google employees. It was designed to make it easier for programmers to create and adapt their work for various situations.

Hiring managers often ask this question to ensure that you possess the basic knowledge necessary for the position. Answer this question in a way that anyone can understand, even if they're not in a technical position. To elaborate on your response, you could explain why some programmers use Go specifically.

2) How do you perform testing in Golang?

For computer programmers, testing is a fundamental practice. However, testing protocols vary from computer programming language to computer programming language. If you want to perform a test in Golang, follow these steps:

  1. Create a new file. End it with _test.go.
  2. Ensure your file contains the required Testxxx functions specific to what you want to test in your package.
  3. Add your test file to the package you intend to test.
  4. Enter your "go test" command. Upon completing the command, the test you wrote and added to the package will run automatically.

To ensure you can implement a necessary feature within the software, the hiring manager might ask you how to do testing in Golang so they can see how clearly you can explain the process. Provide specific, step-by-step instructions on how to run a test in Golang in your response. To make your explanation more clear, try writing the steps out on paper or drawing a chart for the hiring manager.

3) What are the advantages of using an empty struct in Go?

Hiring managers look for applicants who can not only handle basic programming in Golang but also make effective decisions based on their understanding of how the program works. One such test involves asking about the advantages of empty structs. Consider using the STAR method in your answer. STAR stands for:

  • Situation: Provide a situation for your example answer.
  • Task: Explain what your role in the task is.
  • Action: Describe the specific actions you would take.
  • Result: Share the result of your actions.

4) What makes Golang work so fast?

Answering in layman's terms and explaining the benefits of using a speedy language like Golang are your best options.

Example: Golang is incredibly fast, thanks to its design and syntax. Unlike many other programming languages, it has a small syntax and concurrency model, so it is faster. It's also incredibly fast to compile, and it is capable of generating machine code.

5) Can you name the benefits of working in Go rather than another programming language?

Golang offers many advantages for users, especially when compared to other popular coding languages.

  • For one, it is extremely easy to use and relatively concise, making it easier to learn than other languages.
  • Second, it is easy to integrate within your system, as it has built-in support for other widely used programs.
  • Third, it's very fast and it keeps its speed no matter what operating system you're using.
  • Lastly, it automatically manages its memory, which saves space and programming time."

To remember: In your answer, give examples of how Golang could be beneficial to the company for which you are interviewing.

6) What is the static type declaration of a variable in Golang?

Static type variable declarations confirm to the compiler that there is one variable with the given kind and name, which allows the compiler to continue without needing full insight into the variable. Variable declarations are important only at the time of compilation, as the compiler requires an actual declaration at the moment of connecting to the program.

7) Who created Golang?

Golang or Go is an open-source programming language created at Google by Robert Griesemer, Rob Pike, and Ken Thompson. It went live on November 10. 2009.

8) What is the dynamic variable declaration in Golang?

A dynamic kind variable declaration requires an explanation from the compiler regarding the kind of variable based on how much has been transferred to it. To categorize statically as a mandatory condition, the compiler does not need a variable.

9) Is Go case sensitive?

Yes, GoLang is case-sensitive which intimates in Go. Both 'ab' and 'AB' are distinct from one another, so listing them in the same code does not reveal any errors.

10) Mention the packages in Golang?

Like many other programming languages, Go runs on packages as well. A Go program starts with the "main" package; other packages, such as "fmt" and "math/rand", are imported using the word "import".

11) Explain pointers in Go?

Pointers are variables that hold the addresses of variables. In Golang, pointers are also called special variables. The two operators in a pointer are

  • The * operator, also called a dereferencing operator, is used to access the value in the address
  • The & operator, which is also called the address operator, returns the address of a variable

12) What is a constant variable in Go?

As the name implies, constants are fixed in a programming language and their meaning doesn't change. The value of a constant variable must remain the same throughout the program; we cannot change the value of a variable during the program.

13) Declare a constant variable in Golang?

Answer:

package main

import “fmt”

const a=5

Func main{

const AM=” app coursesity”

fmt.println(“hello”, AM)

fmt.println(“hi”, a)

}

14) Name the operators in Golang?

There are six operators in Golang:

  • Relational operators
  • Arithmetic operators
  • Misc operators
  • Bitwise operators
  • Logical operators
  • Assignment operators

15) Explain Methods in Golang?

The only difference between Go methods and Go functions is that the methods of Golang contain receiver arguments. With the cooperation of the receiver argument, the method can determine the characteristics of the receiver.

Syntax:

func(name type) method_name(param_list)(return_type)

{

     //code

}

16) List data types on Golang?

There are four types of data included in the Go language.

  • Interface type
  • Basic type numbers, strings, and booleans
  • Aggregate type structures and arrays
  • Reference type slices, pointers, maps, channels, and functions

17) What is the scope of a variable?

A variable's scope refers to the part of a program in which the variable can be accessed. Go's variables are statistically scoped, which means that the scope of a variable is declared at compile time. There are two types of variables in the Go language:

  • Local variables are variables declared within a function or a block.
  • Global variables are variables declared outside of a function or a block.

18) What is Golang workspace?

Golang workspace includes three directories as its root, the three root directories are:

  • “Bin” contains executable commands
  • "Src" the source file regulated into packages
  • “Pkg” package objects are stored in the directory

19) How to return multiple values from a function?

Golang allows us to return multiple values from a function. The code below shows how to do this.

package main

import “fmt”

func reverse(a,b string)(string, string)

{

return b,a

}

func main()

{

x,y:= reverse(“app”,”coursesity”)

fmt.println(x, y)

}

20) Mention the advantages of Golang?

Advantages:

  • It includes a garbage collector.
  • Compilation is extremely fast.
  • Strings and maps are built into the language
  • Functions in this language are first-class objects

21) Can we declare the multiple types of variables in a single code line in Golang?

We can declare multiple types of variables in a single code declaration as shown below:

var x,y,a= 8, 10.1, “coursesity”

22) What are built-in supports in Golang?

There are five built-in supports in Golang:

  • Database: SQL/database
  • Web server: HTTP/net
  • Compression: gzip/compress
  • Container: heap/container list/ container
  • Cryptography: crypto MD5/ crypto

23) Why was Golang developed?

For app developers, Golang is a great alternative to C++ and Java, particularly in its context as it relates to what Google needs for its network servers and distributed systems. It was designed to eliminate the sluggish pace of large server and software development processes and to make it easier to program for scalability and large systems.

24) Print HelloWorld in Golang?

Answer:

package main

import “fmt”

func main()

{

fmt.println(“Hello World”)

}

25) What is a “slice” in Golang?

Slices are lightweight data structures that are more convenient than arrays. They store homogeneous data in variable-length sequences.

26) What are the decision-making statements in Golang?

In Golang there are four decision-making statements:

  • if Statement: determines whether certain statements are executed.
  • if-else Statement: It will execute a block of code only if a specific condition is true, otherwise, it will not execute the block.
  • Nested if Statement: A nested if is an if statement that is the target of another if or else.
  • if-else-if Ladder: Multiple options are available to a user here. If statements are executed in a top-down manner. When one of the conditions controlling an if is true, the statement associated with that if is executed, and the rest of the ladder is bypassed. When none of the conditions are true, the final else statement is executed.

27) What is the GoPATH variable in Golang?

GoPATH variable is used to denote directories contained in $GoROOT which include all the sources for Go projects, including their binaries.

28) What is the GoROOT variable in Golang?

GoROOT indicates where your Go SDK is located. It is not necessary to modify this variable unless you plan to use multiple versions of Go. Workspace roots are determined by the variable GoPATH.

29) Why do we use the break statement in Golang?

For loops or switches, the break statement is used to permanently stop the loop or switch and write the next statement in rapid succession.

30) Explain structures in Golang?

In Golang, a struct or structure is a user-defined variety that helps a group or combines items of various types into a single type. Each real-world entity that possesses some characteristics can be represented by a structure.

For example, an entity “student” has a name, roll no, and address. The three attributes are better grouped into a single structure, "students", as shown below:

type address struct
{

name string

Rollno int

address string

}

31) Why do we use the continue statements in Golang?

The continue statement in Golang is somewhat similar to the break statement. Upon repeating the loop, it binds the remains of its body and quickly tests its state before repeating.

32) Which kind of conversion is supported by Golang?

Go takes explicit typing very seriously. It is not possible to automate type conversion. When converting a variable from one type to another, explicit type conversion is required.

33) Why do we use a Goto statement in Golang?

The goto statement in the Go programming language jumps unconditionally to a labeled statement within the same function.

Goto statements are discouraged in any programming language because they make it difficult to trace the control flow of a program, making it hard to understand and modify. You can rewrite any program that utilizes gotos using another construct.

34) How can we swap variables in Golang?

Answer:

func swap(sw []int) {

        for a, b := 0, len(sw)-1; a < b; a, b = a+1, b-1 {

                sw[a], sw[b] = sw[b], sw[a]

        }

}
func main() {

    x := []int{3, 2, 1}

    swap(x)

    fmt.Println(x)

    // Output: [1 2 3]

}

35) What is CGo in Golang?

Cgo allows the creation of Go packages that call C code. CGo produces Go and C files that can be merged into a unique Go package from a Go source file that is written with some unique features. Because C represents a "pseudo-package", a name that is unique in cGo and refers to C's namespace

36) What is the channel in Golang?

Channels are communication mediums through which a Goroutine communicates with another Goroutine, and these communications are lock-free. Essentially, a channel is a mechanism by which an individual Goroutine can send data to another Goroutine.

37) Does Golang support inheritance?

Golang does not support inheritance. Nonetheless, on top of the composition, embedding, and interface capabilities it provides code reuse and polymorphism.

38) What are the benefits of learning the Golang programming language?

There are numerous reasons why one should learn Golang. Let's look at them one by one:

  • Easy to learn: The syntax of Golang is similar to C, so Java and C programmers can pick it up quickly. Golang's syntax is smaller and easier to read and write than that of other programming languages.
  • Concurrency: Multithreading applications can be easily written in Golang.
  • Networking: Go is an excellent choice for writing production-level networking applications like TCP or HTTP servers. Go features parsing libraries that can be easily plugged into other services.
  • Tools: Since Golang is open-source, there are already many development tools available.
  • Speedy execution: Go's language execution is very fast compared to other programming languages.

39) Is Go functional or object-oriented?

Go is a Post-OOP programming language that draws its structure (functions, packages, types) from the Pascal/Algol/Modula language family. Go still uses object-oriented patterns for constructing a program that is comprehensible and logical.

40) Explain Goroutines?

In a Goroutine, one function or method runs on another function or method concurrently. The threads are lightweight. As compared to threads, Goroutines are relatively cheap to create. Using goroutines requires you to pass a signal channel to the goroutine, and that signal pushes a value into when you want the goroutine to stop.

41) How to check the variable type at runtime in Golang?

To check the variable type at runtime in Golang, a special switch is used known as a Type Switch. Additionally, you can switch on the type of interface value with Type Switch.

42) How to compare two structs?

The "==" operator can be used to compare two structs, as with any other type. Make sure they do not contain any functions, maps, or slices in which the code cannot be compiled.

43) What's the difference between Unbuffered and Buffered channels?

  • For Buffered channels, the sender will block when a slot is empty on the channel, while the receiver will block when it's empty.
  • Unbuffered channels differ from buffered channels in that the sender blocks the channel until the receiver receives its data. Likewise, the receiver will block the channel until data is sent into it by the sender.

44) Can Go have optional parameters?

Go doesn't support optional parameters, nor does it support method overloading.

45) Does Go have exceptions?

Go does not have exceptions. Multi-value returns in Golang make it easy to report errors without overloading the return value for plain error handling. Go uses error values to indicate abnormalities.

46) What is Rune in Golang?

Rune is a built-in type in Golang, and it's an alias for int32. This value represents a Unicode CodePoint. Runes can represent any code point regardless of how many times it appears. For instance, the rule literal a is number 97 in reality.

47) Explain how to use custom packages in GO language?

You can code like this if you're creating a separate go get -table project for your library and if it's for internal use only:

  • Put the library files under the directory of your project
  • Refer to the path of the library relative to the root of your workspace

For example-

src/
myproject/
mylib/
mylib.go
. . .
main.go

Now, in main.go you could import myprojec/mylib.

48) Explain GO Interfaces?

GO interfaces specify the behavior of objects. Interfaces are created by using the "type" word, followed by a name, and the keyword interface. Interfaces consist of two things.

  • A collection of methods
  • Also, it is referred to as type.

49) Explain how arrays in GO works differently than C?

Array works differently in GO than it does in C

  • In GO, arrays are values and assigning one array to another copies all the elements.
  • Passing an array to a function will result in receiving a copy of the array, not a pointer.
  • An array's size is part of its type. There is a difference between [10] int and [20] int.

50) Explain what Type Assertion is used for and how it does it?

In GO, type conversion is used to convert dissimilar types. Type assertions take an interface property and retrieve a value of the specified explicit type from it.

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