Golang basics Interview Questions And Answers

In 2007, google engineers started to work on a new project; the Go programme. The process of developing the Golang began to solve existing software engineering issues at Google. Finally, in 2012, Google engineers created fresh, dependable, and efficient software.

Golang is an open-source programming language that programmers can use for general purposes in their projects. Other organisations like Cloudflare, Dropbox, MongoDB, Netflix, SoundCloud, Twitch and Uber also use Golang. Moreover, according to many Go projects, below are some critical applications in which developers use Golang:

  • Distributed Network Services
  • Cloud-Native Development
  • Replacements for Existing Infrastructure
  • Utilities and Stand-Alone Tools
  • News Outlets
  • Media Platform

Know More About Golang Basics

To shine in Golang interview questions, you must know that Golang basics includes several features. Below are some essential elements of Golang:

Concurrency: Concurrency is the main feature of the Golang language. In this Language, you can obtain concurrency in your developing project with the help of ‘Go routine’ and channels. Goroutine is very light weight therefore a programmer can easily use it. With the concurrency feature, users can also use multi-processor architecture effortlessly.

Consistency: If you compare the Golang language with other software languages, you will find that it is more straightforward and consistent. It is simpler because of its minimalistic approach and provides consistency by adding a bit more code to the program. Therefore, it is the most popular Language in the programming language market.

Compiler: In Golang, you get a super-fast compiler with an extensive go program that takes only a few seconds to complete. However, the simplicity of the go program’s syntax also helps fast execution.

Pointers: Another fantastic feature of Golang is that it fully supports the pointer, which many modern languages cannot support. However, the concept of C programme and Golang is the same, but the syntax is not.

Standard and comprehensive range toolset: In Golang, users get a wide range of tool sets such as Gorun, Godoc, etc., making the development process easier and more efficient.

Garbage collection: It is a fantastic feature of Golang that handles dangled pointer situations.

Along with excellent features, Golang also has various benefits that can help businesses across multiple sectors. Advantages of Golang that you must know while preparing for Golang interview questions:

  • It has a quick compilation and execution speed
  • You don’t need a virtual machine (VM)
  • Portability
  • Interfaces enable loosely coupled systems
  • Automatic garbage collection
  • It has memory safety
  • Extensive built-in libraries 

1 . What is Golang?

Golang, which some professionals refer to as just “Go,” is a computer programming language invented by programmers at Google in 2009. It is an open-source language, which means that its code is freely accessible to the general public for modification and sharing. Many individuals, organizations and companies use Golang basics as their primary coding language due to its open-source nature

2 . What are packages in Golang?

Packages in Golang basics, which programmers may refer to as “Go packages,” are directories that store Go files. These Go files contain source code, so it is helpful for programmers to use Go packages to maintain records of Go files. Programmers store every piece of code, including functions and variables, in Go files. Then, they can transform these files into a single linked package. Within Golang, every source file resides in a package. It is also possible to place multiple packages inside a single larger package for easier organization.

3 . What is the purpose of a goroutine in Golang?

A goroutine is a function that runs at the same time as other functions. It is common to think of a goroutine as a lightweight thread that operates concurrently with other functions and has independent implementation. This element helps programmers attain concurrency when they are working with Golang. The Go runtime system is responsible for managing all goroutines.

4 . Is Golang a case-sensitive programming language?

Yes, Golang is a case-sensitive programming language. It is essential to write identifiers like function names, variables and language keywords with consistent capitalisation to produce the desired outputs. When you use Golang, capitalization also determines which packages to export.

5 . Can you return multiple values from a function in Golang?

Yes, it is possible to return multiple values from a function in Golang. To produce multiple values, you can send multiple values with the return statement and separate them with a comma. You can also assign the return statement to multiple variables within a single statement. You may use the reverse Values function to return the values in reverse order or use a more traditional function.

6 . Can you declare different variable types within a single line of code?

Yes, it is possible to declare different variable types within a single line of code. Computer programmers and other information technology professionals often do this to create their inputs more efficiently. For example, you can declare variables like a string, a floating-point integer and an integer number on a single line and return concise outputs with ease.

7 . How does Golang work so fast?

Golang is an incredibly fast performing language due to its design. Unlike some other programming languages, it has a small syntax and concurrency model, which helps make it more efficient. Golang’s compilation system operates quickly, and it has the ability to machine code, both of which expedite its pace. One of the most impactful speed-enhancing features of Golang is its storage arrangement. It hyperlinks all the dependency libraries into a single binary file. This reduces the language’s reliance on servers, and it minimizes the data lag you get from this reliance in some other languages.

8 . If you want to grant concurrent data access, is it safer to do so via channels or maps?

Granting concurrent data access is much safer via channels than it is with maps. Channels feature blocking and locking methods that prevent goroutines from sharing memory in the attendance of several threads. Maps do not come with locking methods, so they are not as safe as channels are. If you use maps, you need to implement direct locking methods to send data through goroutines without compromising data security.

9 . What are the three components of a “slice” in Golang?

A slice in Golang is a type of data structure that varies in sequence length and holds elements of the same type. It references an adjacent array segment. Its three components are the pointer, length and capacity. The pointer refers to the first piece of an array that the slice can access. The length is the figure that sums the total elements within the slice. The capacity is by how much the slice is capable of expanding.

10 . What advantages does using Go have over other languages?

  • In contrast to other languages that began as academic experiments, GOlang is designed in a pragmatic way. Each syntax decision and feature is designed to ease the life of the programmer.
  • GOlang is enhanced for concurrency and functions well at scale.
  • Golang basics is much easier to read than other languages because of one standard code format.
  • Automatic garbage collection is much more effective than Python or Java as it runs simultaneously next to the program.

11 . What are string literals?

String constant that resulted from the concatenation of a sequence of characters is represented as a String Literal. It has two forms:

  • Raw string Literals: The value of the raw string literals is the sequence of characters enclosed in backquotes. The string literal value is the string made up of continuous characters in quotes.
  • Interpreted String Literals: You can see it in double quotes. Text in double quotes cannot contain newlines, forming the literal value.

12 . What is Workspace in Golang Basics?

Within a workspace, you must keep a GO code. A workspace is a hierarchy of directories that have three directories in root: src, pkg, and bin.

  • Src holds the GO source files arranged as packages.
  • Pkg includes package objects.
  • Bin includes executable commands

13 . What are the data types in GOlang Basics?

Data types in GOlang include:

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

14 . What is the GOPATH environment variable?

GOPATH environment variable indicates where the workspace should be. This environment variable must be set during the development of the Go code.

15 What are Go interfaces?

Ans: Interfaces are a means of specifying how an object behaves. Using the word “type” followed by the name and keyword interface, an Interface can be created. There are two things that define an interface.

  • It is also called a type
  • Set of methods

15 . What is a rune?

A rune is a built-in type in Go and generally you can know it by int32. In Go, the rune is the Unicode CodePoint. Regardless of the number of bytes the codepoint occupies, it may be represented by rune. A string doesn’t have to be a rune sequence. We may convert from string to rune, but they are not the same.

16 . What is a pointer, and when can we use it?

A pointer contains a value’s memory address and creates a pointer for its operand.

You can use pointers for:

  • Allows a function to transfer a value passed on to it directly.
  • We can use pointers For performance enhancement in extreme cases. In some cases passing large data structures leads to inefficient data replication.
  • To indicate an absence of value.

17 . How to verify a variable type at run time?

The best way to verify the type of a variable on runtime is using a type switch. It examines variables by type but not by value. Every Switch contains a minimum one ‘case’ that acts as the conditional Statement, and the ‘default’ case, it runs if neither case is true. For example, we can create a Type Switch which verifies whether the interface value ‘i’ includes the type ‘string:’ or ‘int’.

18 . Explain about dynamic type declaration of a variable.

Dynamic type declaration of a variable expects a compiler for interpreting the variable as per the value that is passed. The compiler does not require a variable to have the static type as an essential requirement.

19 . Explain about Static type declaration of a variable.

Static type declaration of a variable gives the compiler some assurance that there is an existing variable with the type and name provided to allow the compiler to compile further without the need for full details of the variable. The variable declaration is only meaningful at the time of compilation; the compiler requires a real variable declaration during the program linkage.

20 . Explain When do we use break Statement, continue Statement and go Statement.

  • Break Statement: It is used for the termination of the switch statement or for loop and transfers the execution to the next Statement following the switch statement or for a loop.
  • Continue Statement: It makes the loop easier to jump the rest of its body and immediately reassess one’s state before repeating it.
  • Go Statement: Using this, the control is transferred to the labeled Statement.

21 . How unbuffered and buffered channels differ?

In the case of an unbuffered channel, the sender blocks the channel till the data is reached to the receiver from the channel, while the receiver blocks the channel till the data is sent into the channel by the sender.

In comparison with the unbuffered channel, in the buffered channel, the sender will block when no empty slot is available.

22 . Explain the purpose of Type assertion.

Type conversion is intended to convert different types in GO. A type assertion will take an interface value and fetch a value of the explicitly specified type.

21 . What’s so unique about constants in Golang Basics?

Go’s constants are unique. 

  • Untyped Constants:  A constant in GOlang, unnamed or named, is untyped except if a type is explicitly given. For example, an untyped floating-point constant such as 4.5 may be used wherever a floating value is permitted. Untyped constants may be used to temporarily escape the strong type system of the Go system till they are evaluated in a type-demanding expression.
  • Typed Constants: If we specify the type in the declaration explicitly they are typed constants. All the flexibility available with untyped constants, such as allocating them to any of the compatible types or mixing them with the mathematical operations, are lost using typed constants. In general, we would need to declare a constant type only when absolutely necessary.

23 . How do you write multi-line strings in Golang basics?

In GOlang, for writing a multi-line string, we use a raw string literal; here, the string delimits by backquotes instead of double-quotes.

Example: 

First line

Second line

Third line

24 . How do arrays in Go work differently than C?

In GO, Array functionality is different than in C. 

  • Arrays are the values; When we assign an array to another array, it will copy all the elements. 
  • If we pass an array to a function, it will get a copy of that array rather than a pointer.
  • The array size is part of its size.

25 . Is it possible to compile a Go program written in Linux on a Windows/Mac system?

Yes, it’s possible to compile a Go application for different operating systems.

26 . What is the constant variable in Golang Basics?

A constant variable is one that has a specific value and cannot be changed.

27 . What are variadic functions in Go?

A variadic function accepts various numbers of arguments. A variable number of parameters of the same type as those in the function signature are in Golang.

28 . Differentiate between const and read-only keywords.

Const: 

  • These variables are evaluated at compile time
  • They are only for value types 

 Read-only: 

  • These variables are evaluated at runtime
  • They can hold reference type variables

29 . Explain the Golang map type and its advantages.

In Golang, map is a very powerful and versatile unordered data structure. A map is a collection of element group in key-value pairs. Similar to a dict in python and an object in JS. Awareness of the keys in maps can easily provide faster access to the values. The Values and the keys have to be of the same statistical type. Although both keys and values do not have to be of the same type, rather in terms of individuality all the values present on the map should be of the same type.

30 . What is garbage collection in Golang Basics?

Garbage collection recycles storage that has been dynamically assigned to a program for use by other objects. The term typically refers to the waste collector’s automated regeneration for routine storage rather than explicit code (written by a programmer) to release specific memory blocks.

Automatic garbage collection is frequently initiated when the amount of free RAM falls below a predetermined level or after a predetermined number of allocations. The removal of items that the software no longer requires to make room in memory for other dynamic objects is “garbage collection.”

31 . What is Regex?

A regular expression is abbreviated as regex. It demonstrates how to format a pattern for text searches. More rules, specifically those dealing with character groups, string position, and so on, work for our use cases. The REGEX syntax is nearly identical across all computer languages.

32 . What are timers and tickers in Golang basics?

Timers represent a single future event. They plan one-time future actions. Tickers schedule recurring tasks at regular intervals.

33 . Select and switch in Golang?

A select works with channels, a switch is used with concrete types. A select will choose multiple valid options at random, while a switch will go in sequence (and would require a fallthrough to match multiple.)

34 . Is Go functional or object-oriented?

Go is a Post-OOP programming language that borrows the Pascal/Algol/Modula language family’s structure (functions, packages, and types). Object-oriented patterns are still useful in Go for structuring programs in a clear and understandable manner.

 35 . Errors and Exception Handling in GoLang

Go functions return errors as a second return value. That is the standard way of implementing and using errors in Go. That means the error can be checked immediately before proceeding to the next steps.

36 . Is it recommended to use global variables in a program that implements go routines?

Global variables are not recommended because they can be accessed by multiple goroutines (threads) concurrently, which can easily lead to unexpected behaviour and arbitrary results.

37 . List the operators in Golang basics

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

38 . What are function closures?

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

39 . What are rvalue and Ivalue?

Golang supports two kinds of expressions:

  • lvalue − The expressions refer to as memory locations popular 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 store 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.

40 . What are built-in supports in Golang basics?

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

 41 . 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

 42 . 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 top-down. As soon 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.

 43 . 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.

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

The Goto statement works to assign control to the labelled statement.

 45 . 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 merge 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.

46 . 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.

47 . How to perform testing in Golang?

In Golang, package testing supports automated testing. It is works 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. 

48 . 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.