Go Interview Questions and Answers

Q1. What is Go?

Ans: 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?

Ans: 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?

Ans: 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 to variables in Golang?

Ans: 

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]

}

Q5. Mention the packages in Golang?

Ans: 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?

Ans: 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.

Q7. Explain pointers in Go?

Ans: 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 utilised to return the address of the variable

Q8. What is a constant variable in Go?

Ans: 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?

Ans:

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?

Ans:

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

Q11. List data types on Golang?

Ans: 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?

Ans: 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?

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Ans: There is only one difference between Go methods and Go functions that is methods of Golang contains 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?

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

“Src” the source file regulated into packages 

“Pkg” package objects are stored in the directory

“Bin” it contains executable commands

Q15. How to return multiple values from a function?

Ans: 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?

Ans: 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?

Ans:

  • It contains garbage collector
  • Go compiles very quickly
  • Maps and strings are built into the language
  • First-class objects are functions in this language

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

Ans: 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?

Ans: 

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

Q20. Why does Golang developed?

Ans: 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?

Ans:

package main

import “fmt”

func main()

{

fmt.println(“Hello World”)

}

Q22. What is “slice” in Golang?

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

Q23. What are decision making statements in Golang?

Ans: There are 4 decision-making statements in Golang they are

  • if statement: used to decide whether certain statements will be executed or not 
  • 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
  • Nested-if statement: nested if means if condition inside another 
  • if condition
  • 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?

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

Q25. What is GoROOT variable in Golang?

Ans: 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 regarding your workspace.

Q26. Explain structures in Golang?

Ans: 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 which 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 break statement in Golang?

Ans: The break statement is utilised 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 continue statement in Golang?

Ans: The continue 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?

Ans: The Goto statement is utilised to assign control to the labelled statement.

Q30. What is the channel in Golang?

Ans: 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 which enables an individual Goroutine to send data to a different Goroutine. 

Q31. Explain about switch statement in Golang?

Ans: 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 same as 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: Type switch is utilised 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?

Ans: 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?

Ans: 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?

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

Q35. What is CGo in Golang?

Ans: CGo allows Go packages invite C code. Given a Go source file which 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