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Go (Golang) Interview Questions

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by Ravindra Savaram
Last modified: July 16th 2021

Go or Golang, the popular and open-source programming language from Google. Today's top business giants like BBC, Netflix, Uber, and more are also using Golang to scale their products and achieve high performance. Hence, there is always a great demand for professionals to work in this field. But, how do you get yourself a job in the field of Golang? Well, we have answers to that!

Inclined to build a profession as GO Developer? Then here is the blog post on, explore GO Training

In this Golang Interview Questions blog, we'll talk about the important Golang Questions which could be asked in your next Golang interview. We'll look into questions from the very basics to advanced-level concepts of Go.

Top 10 Frequently Asked Go Interview Questions

  1. What is Go?
  2. How can we swap variables in Golang?
  3. Explain pointers in Go?
  4. List the operators in Golang?
  5. Explain Methods in Golang?
  6. What is Golang workspace?
  7. Mention the advantages of Golang?
  8. Why does Golang develop?
  9. What are the decision-making statements in Golang?

Top Golang Interview Questions and Answers

Q1. What is Go?

Go is also known as GoLang, it is a general-purpose programming language designed at Google and developed by Robert Griesemer, ken Thomson and Rob Pike. It is a statistically typed programming language used for building fast and reliable applications.

Q2. What is the static type declaration of a variable in Golang?

Static type variable declaration gives confirmation to the compiler that there is one variable existing with the given kind and name so the compiler continues for an additional compilation without requiring total insight concerning the variable. A variable declaration holds its importance at the moment of compilation only, the compiler requires actual variable declaration at the moment of connecting to the program.

Q3. What is the dynamic variable declaration in Golang?

A dynamic kind variable declaration needs the compiler to explain the kind of the variable based on the amount transferred to it. The compiler doesn’t need a variable to cateGorise statically as a mandatory condition.

Q4. How can we swap variables in Golang?

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]

}

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Q5. Mention the packages in Golang?

As many of the programming languages, the Go programming language also runs on packages, like any other programming Go program also starts for the “main” package, other packages like “fmt”, “math/rand” are imported using the “import” keyword.

Q6. Is Go case sensitive?

True, GoLang is case sensitive which intimates in Go

'ab' and 'AB' are diverse from each other and it doesn't disclose any error if we list these couple of variables in the same code.

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Q7. Explain pointers in Go?

Pointers are variables that hold the address of any variable. Pointers in Golang are likewise called special variables. There are two operators in pointers they are

  • * operator which is also called a dereferencing operator used to access the value in the address 
  • & operator which is also called as address operator this is utilized to return the address of the variable

Q8. What is a constant variable in Go?

As the name suggests constant means fixed and the meaning doesn’t change in a programming language. Once the value of a constant variable is defined then it should be the same throughout the program, we cannot change the value of a variable in between the program

Q9. Declare a constant variable in Golang?

package main

import “fmt”

const a=5

Func main{

const AM=” app majix”

fmt.println(“hello”, AM)

fmt.println(“hi”, a)

}

Q10. List the operators in Golang?

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

Q11. List data types on Golang?

There are 4 data types in the Go language

  1. Basic type numbers, strings, and booleans
  2. Aggregate type structures and arrays
  3. Reference type slices, pointers, maps, channels, and functions
  4. Interface type

Q12. What is the scope of a variable?

The scope of a variable means the part of a program where the particular variable can be accessed. In the Go language, every variable is statistically scoped that means the scope of a variable is declared at compile time itself.

Scope of a variable in the Go language is cateGorized into two types

Local variables these variables are either declared inside a function or a block

Global variables these variables are declared outside the function or a block

Q13. Explain Methods in Golang?

There is only one difference between Go methods and Go functions that is the methods of Golang contain receiver argument in them. The method can obtain the characteristics of the receiver with the cooperation of the receiver argument.

syntax:

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

{

     //code

}

Q14. What is Golang workspace?

The workspace of Golang includes three directories as its roots, workspace carries Go code, the three root directories are:

  1. “Src” the source file regulated into packages 
  2. “Pkg” package objects are stored in the directory
  3. “Bin” contains executable commands

Q15. How to return multiple values from a function?

We can return multiple values from a function in Golang, the below code shows how we can return multiple values

package main

import “fmt”

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

{

return b,a

}

func main()

{

x,y:= reverse(“app”,”majix”)

fmt.println(x, y)

}

Q16. Is GoLang fast?

Golang’s concurrency model and small syntax make Golang fast programming language, Golang compilation is very fast, Go hyperlinks all the dependency libraries into a single binary file, as a result, putting off the dependence on servers. 

Q17. Mention the advantages of Golang?

  • It contains a garbage collector
  • Go compiles very quickly
  • Maps and strings are built into the language
  • First-class objects are functions in this language
  • Golang is faster than other programming languages, which enhances the availability and reliability of services.
  • It's easy to learn.
  • Another significant advantage of using Golang is its ability to support concurrency.
  • Professionals with Golang expertise are growing. The demand for this programming language is increasing and is ranking under the top 10 positions for the last few years under various language ranking indices.

Q18. How can we declare the multiple types of variables in a single code line in Golang?

Yes, we can declare various type variables in a single code declaration like the example below:

var x,y,a= 8, 10.1, “appmajix”

Q19. What are built-in supports in Golang?

  • Web server: http/net 
  • Container: heap/container list/ container
  • Cryptography: crypto md5/ crypto
  • Database: sql/database
  • Compression: gzip/compress

Q20. Why does Golang develop?

Golang is developed out of the difficulty in existing environments and languages for system programming.

Go is an effort to have:

  • Dynamically typed language and interpreted language
  • Compiled language and the safety and efficiency of statistically typed
  • To be fast in the compilation
  • To support the multi-core computing

Q21. Print HelloWorld in Golang?

package main

import “fmt”

func main()

{

fmt.println(“Hello World”)

}

Q22. What is “slice” in Golang?

Slice is a lightweight data structure that is convenient than an array, the slice is a variable-length sequence that stores the homogeneous type of data. 

Q23. What are the decision-making statements in Golang?

There are 4 decision-making statements in Golang they are

  1. if statement: used to decide whether certain statements will be executed or not 
  2. if-else statement: if a certain condition is true only then it will execute a block if it is not true then it won’t execute the block of code
  3. Nested-if statement: nested if means if condition inside another 
  4. if condition
  5. if-else-if ladder: Here, a user can choose among various options. The if statements are executed of top-down. As early as one of the states controlling the if is correct, the statement compared with that if is executed, and the remaining ladder is bypassed. If none of the conditions is correct, then the last else statement will be executed.

Q24. What is the GoPATH variable in Golang?

The GoPATH environment variable is employed to symbolized directories out of $GoROOT that combines the source for Go projects including their binaries.

Related Article: Golang Tutorial for Beginners

Q25. What is the GoROOT variable in Golang?

GoROOT is a variable that determines wherever your Go SDK is located. You do not require to modify this variable except you plan to use various Go versions. GoPATH is a variable that determines the root of your workspace.

Q26. Explain structures in Golang?

A struct or a structure of Golang is a user-defined variety that helps the group or combines items of various types into a single type, each real-world entity that holds some characteristics can be represented as a structure.

For example, an entity “student” has a name, roll no, address. It gives the sense to group these three attributes into a single structure “student” as shown

type address struct

{

name string

Rollno int

address string

}

Q27. Why do we use the break statement in Golang?

The break statement is utilized to stop the for loop or switch statement and assign execution to the statement quickly following the for loop or switch.

Q28. Why do we use the continued statements in Golang?

The continued statement promotes the loop to bound the remains of its body and quickly retest its state preceding to repeating.

Q29. Why do we use a Goto statement in Golang?

The Goto statement is utilized to assign control to the labeled statement.

Q30. What is the channel in Golang?

A channel is a communication medium through which a Goroutine communicates with different Goroutine and this communication is lock-free. Practically, in other words, a channel is a method that enables an individual Goroutine to send data to a different Goroutine. 

Q31. Explain about switch statement in Golang?

A switch statement is a multi-way branch record. It gives an effective way to assign the execution to various parts of code based upon the utility of the expression. Go language holds two types of switch statements they are

Expression switch: expression switch in Golang is the same as the switch statement in C, C++, Java languages, It gives an effortless way to dispatch execution to various parts of code which is based upon the value of the phrase.

Syntax:

switch optstatement; optexpression

{

case exp1: statement

case exp2: statement

…..

default: statement

}

Type switch: A Type switch is utilized when you require to match types. In this switch, the case includes the type which is operating to compare with the type existing in the switch expression.

Syntax:

switch optstatement; type switchexpression

{

case type1: statement

case type2: statement

…..

default: statement

}

Q32. Which kind of conversion is supported by Golang?

Go is very particular about explicit typing. There is no automated type conversion. Explicit type conversion is needed to designate a variable of one type to another.

Q33. What is an interface in Golang?

Go language interfaces differ from other languages. In Go language, the interface is a system type that is applied to designate a set of 1 or more method signatures plus the interface is abstract, so you are not permitted to create a case of the interface.

Syntax:

type nameof_interface interface

{

//Signature of method

}

Q34. What is a select statement in Golang?

In Go language, the select statement is just similar to a switch statement, however, in the select statement, the case statement indicates communication, i.e. sent or receive progress on the channel.

Q35. What is CGo in Golang?

CGo allows Go packages to invite C code. Given a Go source file that is written with some unique features, cGo yields Go and C files that can be merged into a unique Go package. That is because C means a "pseudo-package", a unique name defined by cGo as a reference to C's namespace

Q36. Why should one learn the Golang programming language?

There are various reasons why one should learn the Golang programming language. Let's see one by one:

  • Easy to learn: The syntax of the Golang programming language is similar to that of C, and it's easy to pick up for C or Java programmers. Compared to other programming languages, Golang's syntax is smaller than others and easy to read and write programs.

  • Concurrency: Creating multithreading applications using the Golang language is easy.

  • Networking: Go is excellent for writing networking applications like TCP or HTTP servers at the production level. Go supports parsing libraries that are easy to plug into other services.

  • Tools: As Golang is open-source, there are large development tools that are already present.

  • Speedy execution: compared to other programming languages, Go's language execution is very fast.

Q37. Who created Golang?

Golang or Go, an open-source programming language designed at Google by Robert Griesemer, Rob Pike, and Ken Thompson. It was made available from Nov 10. 2009. 

Q38. Does Golang support inheritance?

Golang doesn't have the inheritance concept. But to support code reuse and polymorphism functionality, it provides a composition, embedding, and interfaces.

Q39. Is Go functional or object-oriented?

Go is a Post-OOP programming language that borrows the structure (functions, packages, types) from the Pascal/Algol/Modula language family. In Go, object-oriented patterns are still helpful to structure a program in a clear and understandable way.

Q40. Explain Goroutines?

Goroutines are functions or methods which run on other functions or methods concurrently. They are lightweight threads. The cost of creating Goroutines is small compared to threads. To stop using goroutines, you need to pass a signal channel to the goroutine, and that signal pushes a value into when you want the goroutine to stop.

Q41. How to perform testing in Golang?

In Golang, package testing supports automated testing. It is designed to be used with the "go test" command, which automates the execution of any form's function.

To write a test, you need to create a file with a name ending in _testing. 

Q42. How to check the variable type at runtime in Golang?

In Golang, to check the variable type at runtime, a special type of switch is used and is referred to as a type switch. Also, you can switch on the type of interface value with Type Switch.

Q43. How to compare two structs?

You can compare two structs with the "==" operator, as you would do with other types. Make sure they don't contain any functions, maps, or slices in which the code will not be compiled.

Q44. Does Go have exceptions?

No, Go doesn't have exceptions. Golang's multi-value returns make it easy to report errors without overloading the return value for plain error handling. Error-values are used to indicate an abnormal state in Go.

Q45. Can Go have optional parameters?

Go does not have optional parameters, nor does it support method overloading.

Q46. What's the difference between unbuffered and buffered channels?

  • For the buffered channel, the sender will block when there is an empty slot of the channel, while the receiver will block on the channel when it's empty.

  • Compared with the buffered counterpart, in an unbuffered channel, the sender will block the channel until the receiver receives the channel's data. Simultaneously, the receiver will also block the channel until the sender sends data into the channel.

Q47. What is Rune in Golang?

A rune is a built-in type in Golang, and it's the alias of int32. It represents a Unicode CodePoint. It doesn't matter how many times the code point occupies; a rune can represent it.

For example, the rule literal a is number 97 in reality.

A string is not a sequence of runes.  

Q48. What are function closures?

In Golang, anonymous functions are called function closures. They are used in dynamic programming.

Q49. What are rvalue and Ivalue?

Golang supports two kinds of expressions:

  • lvalue − The expressions which are referred to as memory locations are known as "lvalue" expressions. It appears either on the right-hand or left-hand side of an assignment operator.

  • rvalue − It refers to a data value that is stored at some address in memory. It cannot have a value assigned to it. So rvalues always appear on the right side of the assignment operator.

About Author

author
NameRavindra Savaram
Author Bio

 

Ravindra Savaram is a Content Lead at Mindmajix.com. His passion lies in writing articles on the most popular IT platforms including Machine learning, DevOps, Data Science, Artificial Intelligence, RPA, Deep Learning, and so on. You can stay up to date on all these technologies by following him on LinkedIn and Twitter.