Golang is a powerful programming language developed by Google for building cloud applications and command line tools. It has a vibrant and growing community as a product of Google making it an ideal choice of many developers. The popularity of Go has been increasing continuously since its public release in 2012 due to its speed and concurrency.
According to the US Bureau of Labour Statistics, Computer and IT jobs are expected to grow much faster than average from 2023 to 2033, with a projected 356,700 job openings annually. Therefore it is the right time to start a career with Go programming language. But how? Well, we have compiled a collection of expertly curated most asked Golang interview questions in this blog. These will set you apart and help you secure your next opportunity.
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Here are the frequently asked Golang interview questions and answers for freshers.
Go programming language is full of powerful features, including-
Packages in Go language refer to an accumulation of source files in one directory. Go programs generally get organized into packages. The key thing to note here is that constants, functions, types and variables get stored in a single source file. All source files that are within the same package are visible to one another.
The two types of operators you can use in Go language are - ' * ' and ' & '. The former is used for declaring a pointer, while the latter is used for getting the address of a variable.
The operators in Go are-
Go (language) variable scope is a part of the program that can be defined in a method, loop, class, etc. It allows us to access and modify specified variables. Scope variables are divided into two categories, namely global variables and local variables. Global variables are declared outside a block or function code. Local variables are generally declared inside a block or function code.
Yes, Go is a case-sensitive language.
It is so popular because of the various features it possesses and benefits it offers. Here are a few of them-
The 4 types of constants in Go language are-
Data Type in Go language pertains to the specific type of data that can be held by a valid Go variable. In the Go programming language, the data type is divided into four categories, namely -
In Go language, methods refer to specific functions associated with a certain type. Methods facilitate developers in defining the behavior for the objects of that type. Since the Go programming language is not a complete object oriented language (OOP), it does not support classes. Thus, to replicate the behavior of classes, methods on types are put to work.
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Here are some of the most important Golang interview questions for intermediates. These will help you to take your one step further and secure a senior Go language developer or engineer role.
Pointers in Go is a powerful feature that facilitate in manipulating the memory addresses and directly accessing the data in the memory. Pointers are commonly used for returning values from the functions by reference, creating references to variables and passing arguments to functions through reference.
In Go programming language, programs are compiled in a directory hierarchy, known as workspace. It has three main components
The init () function in Go (language) is employed for initializing the app state prior to executing the main function. It is possible for a package to have more than one init function. All of these get executed prior to the main package's main function.
Built-in supports in Go programming language include-
Structs or structures in Go programming refer to a user-defined type for storing an accumulation of various fields into a single one. In simpler terms, data of varying types can be combined together with structures.
type person struct { name string age int height int}
Creating a custom type in Go requires using the type keyword. It is the combination of the name of type and the underlying type it is based on. Custom type is mostly useful in creating abstractions and improving code readability. For instance, I want to create a custom type called individual based on the string type. It will require the type use of that string.
An empty struct in Go language takes the role of a placeholder for defining a type that may be used as a return type of a function or in generic programming. Additionally, using an empty struct leads to improved code readability and aids in avoiding memory wastage.
Go maps are Concurrent safe for 'read only'. Since they do not have a locking mechanism, explicit locking mechanisms such as Mutex, must be used to safely send data via Goroutines.
GOPATH facilitates in specifying the root directory of the Go workspace. GOROOT, on the other hand, pins the location of the Go installation directory. It does not need to be changed if you do not wish to use other Go versions. Both of these are environment variables.
Statically typed language or static type is responsible for checking the variable's type initially in the programming life cycle during compilation. Dynamically typed languages or the dynamic type in Go programming are able to update types during runtime.
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The 'sync' package provides an array of tools that can be employed for protecting shared data from being accessed by various goroutines concurrently. Using a mutex is one of the most widely chosen ways to make it happen. A mutex refers to a synchronization object, with the ability to be used to protect a resource. The aim is to ensure that a single goroutine can access it at a given time. A new instance of the sync.Mutex struct must be created to use a mutex. Afterwards, the Lock and Unlock methods are employed for protecting the critical code section.
To embed a struct in Go language, we will first declare a field in it and then assign the value of another struct to it. Once done, this field carrying the struct value is referred to as an embedded struct. Dot notation can be used with the parent struct to access the field of the embedded struct, facilitating us in reusing the methods and the fields.
Goroutines refer to a function executed concurrently along the program and a lightweight execution thread in Go programming. Since the overhead needed to create a goroutine is extremely low, they prove to be extremely cheap in comparison to the traditional threads.
Quit : = make (chan bool) go func ( ) { for { select { case <- quit: return default // do other stuff } } }() // Do stuff // Quit goroutine Quit <- true
Both byte and rune are the fundamental elements to store and process data in a computer system. These are typically used in programming languages to customize strings and characters.
A byte is the smallest unit of data a computer can address generally represented in hexadecimal notation. It consists of 8 bits of data representing a numerical value, single character or an instruction.
A rune is a Unicode character in Go programming language that represents a single code point or a symbol. It can be anything in a script like digits, alphabet or punctuation. Its size may vary from a single byte to 4 bytes. It represents characters from different scripts and languages.
GoPath and Goroot are the two different variables that define the alignment of source code. The following are some of the key differences between them -
| Feature | GOROOT | GOPATH |
| Purpose | Location of Go installation | Workspace for Go projects |
| Contains | Standard library, compiler, tools | Source code, packages, binaries |
| Default Path | /usr/local/go or C:\Go | $HOME/go |
| Need of Modification | Rarely | Often set by developers |
Variadic functions are responsible for providing a variable number of arguments to a particular function. The number of functions is not predefined, making it useful when the developer does not know how many numbers to pass. The only restriction in this process is that one can only use a single type of arguments.
Shadowing means an outer variable is temporarily inaccessible within the innerscope. It often occurs when a variable with the same name as another outer variable is defined inside the innerscope. Shadowing can lead to potential bugs and errors or make it hard to read and understand the code. The developer may also unexpectedly change the inner variable instead of the outer one and vice versa.
Let's understand with the following code snippet -
package main import "fmt" func main() { x := 10 // Outer x fmt.Println("Outer x:", x) { x := 20 // Inner x (shadows the outer x) fmt.Println("Inner x:", x) } fmt.Println("Outer x:", x) } |
In this example, the x inside the curly braces shadows the x from the main function. This means developers can get confused to detect the right one. It requires careful handling and using best practices to avoid this issue.
Buffered vs. Unbuffered Channels in Go -
| Feature | Unbuffered Channels | Buffered Channels |
| Communication Style | Synchronous | Asynchronous |
| Data Storage | No buffer (direct transfer) | Buffer with a defined capacity |
| Blocking Behavior (Send) | Blocks until a receiver is ready | Get blocked when the buffer is full |
| Blocking Behavior (Receive) | Blocks until a sender is ready | Get blocked when the buffer is empty |
| Synchronization | Strict "handshake" synchronization | Decoupled, more flexible |
| Use Cases | Strict synchronization between goroutines, handshake communication and ensuring immediate action by another goroutine. | Handling bursts of data, decoupling senders and receivers, implementing queues and rate limiting. |
| Analogy | A direct phone call - Both parties must be present to communicate. | A postal mailbox - Senders can drop off mail and receivers can collect it later. |
| Key Advantage | Ensures that two goroutines synchronize on some event. | Allow for more flexible communication patterns. |
| Key Disadvantage | Prone to deadlocks if not handled carefully. | Requires careful consideration of buffer size to avoid excessive memory usage. |
There are multiple method to stop goroutine after spawning, some of them are as follows -
Using a context of cancellation -
ctx, cancel := context.WithCancel(context.Background()) go func(ctx context.Context) { for { select { case <-ctx.Done(): fmt.Println("Goroutine stopped") return default: // Do work } } }(ctx) cancel() // Stops the goroutine |
Using a channel -
stop := make(chan struct{}) go func(stop chan struct{}) { for { select { case <-stop: fmt.Println("Goroutine stopped") return default: // Do work } } }(stop) close(stop) // Stops the goroutine |
There are multiple best practices to format a Go language source code in an idiomatic way. Each of them ensures that the codes are readable and maintainable. Here are some of them -
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If you want to become more technical during interview rounds then follow these Golang coding interview questions and answers.
for init; condition; post { // statements } for condition { // statements } for key, value := range collection { // statements } |
The 'func' keyword is used to create the function literal in Go language. Formal parameters within the parentheses follow this, along with the function body encircles within curly braces. This is how the syntax looks like -
The syntax to create and use a type assertion includes inserting the keyword .(type) post the value that you intend to assert the type of. This is an example to help you -
Some people prefer to use an empty struct {} as it helps in saving some memory, since they do not have any memory for its value.
a := struct{}{}println(unsafe.Sizeof(a))// Output: 0 |
To have a hash displayed in a fixed order, we would need to sort its keys.
package main import ( "fmt" "sort" ) func main() { fruits := map[string]int{ "oranges": 100, "apples": 200, "bananas": 300, } // Put the keys in a slice and sort it var keys []string for key := range fruits { keys = append(keys, key) } sort.Strings(keys) // Display keys according to the sorted slice for _, key := range keys { fmt.Printf("%s: %v\n", key, fruits[key]) } } |
Output:
apples: 200 bananas: 300 oranges: 100 |
And. Yes, it's possible to write multiple strings in Go language. It can be done by using a raw string literal, wherein it is delimited by back quotes.
For instance-
str := `line 1 line 2 line 3` fmt.Println(str) |
sync.Pool caches the unused and allocated items to reduce garbage collection.
pool := &sync.Pool{ New: func() interface{} { return make([]byte, 1024) }, } |
To format a string without printing, use this command-
return fmt.Sprintf ("at %v, %s" , e.When , e.What ) |
Compiling a Go program in different operating systems requires implementing a cross compilation technique. This technique involves using GOARCH and GOOS environment variables to denote the architecture and target OS. These are in-built in the system's architecture and can be seen by the go env command.
Cross compile Go for Windows -
# for 64-bit GOOS=windows GOARCH=amd64 go build -o bin/app-amd64.exe app.go # for 32-bit GOOS=windows GOARCH=386 go build -o bin/app-386.exe app.go |
Cross compile Go for Mac -
# for 64-bit GOOS=darwin GOARCH=amd64 go build -o bin/app-amd64-darwin app.go # for 32-bit GOOS=darwin GOARCH=386 go build -o bin/app-386-darwin app.go # for Apple Silicon GOOS=darwin GOARCH=arm64 go build -o bin/app-arm64-darwin app.go |
Type assertion provides a simple way to access the value of the data types available in the interface. In simple words, if a data type of a variable is available in an interface, it will directly retrieve the actual value of that data type. Its syntax is as follows -
t := value.(typeName) |
In this syntax, the value is the variable whose type is available in the interface and the typeName is concrete type. This assigns the typeName value to another variable t. Here is an example of its use -
// Golang program to illustrate // the concept of type assertions package main import ( "fmt" ) // main function func main() { // an interface that has // a string value var value interface{} = "igmGuru" // retrieving a value // of type string and assigning // it to value1 variable var value1 string = value.(string) // printing the concrete value fmt.Println(value1) // this will panic as interface // does not have int type var value2 int = value.(int) fmt.Println(value2) } |
igmGuru panic: interface conversion: interface {} is string, not int |
// SampleStruct definition type SampleStruct struct { Num int } // A. func exampleFunc() SampleStruct { return SampleStruct{Num: 10} } // B. func exampleFunc() *SampleStruct { return &SampleStruct{Num: 20} } // C. func exampleFunc(s *SampleStruct) { s.Num = 30 } |
This code includes pointer receivers, memory allocation and modification functions.
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Interviewers may also ask candidates to develop different types of programs when going for a Go developer interview. Therefore, it is also important to know how to deal with these questions. Let's explore some of them -
package main import "fmt" func swapContents(listObj []int) { for i, j := 0, len(listObj)-1; i < j; i, j = i+1, j-1 { listObj[i], listObj[j] = listObj[j], listObj[i] } } func main() { listObj := []int{1, 2, 3} swapContents(listObj) fmt.Println(listObj) } |
Output -
[3 2 1] |
Let's take the number as 10.
package main import "fmt" //factorial function func factorial(n int) int { if n == 0 { return 1 } return n * factorial(n-1) } func main() { fmt.Println(factorial(10)) } |
Output -
3628800 |
package main import "fmt" func do(i interface{}) { switch v := i.(type) { case int: fmt.Printf("Double %v is %v\n", v, v*2) case string: fmt.Printf("%q is %v bytes long\n", v, len(v)) default: fmt.Printf("I don't know type %T!\n", v) } } func main() { do(21) do("hello") do(true) } |
func perm(a []rune, f func([]rune), i int) { if i == len(a) { f(a) return } for j := i; j < len(a); j++ { a[i], a[j] = a[j], a[i] perm(a, f, i+1) a[i], a[j] = a[j], a[i] } } |
package main import "fmt" func reverse(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} reverse(x) fmt.Println(x) } |
fib(0)=0 fib(1)=1 fib(2)=1+0 = 1 fib(3)=1+1 = 2 fib(4)=2+1 = 3 : : fib(n)=fib(n-1)+fib(n-2) |
Ans.
package main import "fmt" //nth fibonacci number function func fibonacci(n int) int { if n < 2 { return n } return fibonacci(n-1) + fibonacci(n-2) } func main() { fmt.Println(fibonacci(7)) } |
Output -
13 |
package main import ( "bytes" "fmt" ) func main() { sl1 := []byte{'I', 'N', 'T', 'E', 'R' , 'V', 'I', 'E', 'W'} sl2 := []byte{'B', 'I', 'T'} // Use Compare function to compare slices res := bytes.Compare(sl1, sl2) if res == 0 { fmt.Println("Equal Slices") } else { fmt.Println("Unequal Slices") } } |
Output -
Unequal Slices |
type singleton struct{} var instance *singleton var once sync.Once func getInstance() *singleton { once.Do(func() { instance = &singleton{} }) return instance } |
package main import ( "testing" ) func Add(a, b int) int { return a + b } func TestAdd(t *testing.T) { cases := []struct { name string input1 int input2 int want int }{ {"positive numbers", 2, 3, 5}, {"negative numbers", -1, -1, -2}, } for _, c := range cases { t.Run(c.name, func(t *testing.T) { got := Add(c.input1, c.input2) if got != c.want { t.Errorf("Add(%d, %d) = %d; want %d", c.input1, c.input2, got, c.want) } }) } } |
package main import "fmt" func findMax(nums []int) int { if len(nums) == 0 { return 0 // Or handle error appropriately } max := nums[0] for _, num := range nums[1:] { if num > max { max = num } } return max } func main() { x := []int{5, 12, 3, 8, 20} maxVal := findMax(x) fmt.Println("Max:", maxVal) } |
In Go 1.22, each iteration of a "for" loop creates its own instance of loop variables, which prevents the common "closure capturing the loop variable" bug when launching goroutines inside loops.
|
for _, v := range []string{"a", "b", "c"} { go func() { fmt.Println(v) // now safely prints "a", "b", "c" }() } |
Go 1.22 allows you to loop over a numerical range directly. For instance, for i := range 10 will iterate i from 0 to 9. It provides a compact alternative to classic for i := 0; i < n; i++ syntax.
|
for i := range 5 { fmt.Println(i) // Prints 0 to 4 } |
Go 1.22 delivers runtime optimizations. Its CPU performance sees a 1–3% boost and memory usage drops by around 1%. Also profile-guided optimization (PGO) improves devirtualization, with many programs seeing 2–14% faster execution when PGO is enabled.
net/http.ServeMux router?Go 1.22 upgrades ServeMux to support method-based matching and wildcard routes. Patterns like GET /task/{id}/ now work natively, which reduces the need for third-party routing libraries.
Several valuable tools were added in Go 1.22:
math/rand/v2: A revamped, faster, and more consistent random-generation API.database/sql.Null[T]: Offers a generic nullable type for scanning SQL columns cleanly.slices.Concat: A utility to concatenate multiple slices of any type in one call.
Becoming a pro in Go language requires you to enroll in a leading course being offered by a trusted learning platform or you can go through the comeplete Golang tutorial to learn more about the Go programming language. If you wish to ace your Golang interview and get the job that helps you excel, then you must prepare well with these Golang interview questions and answers. We hope these interview questions and answers help you ace your interview.
Golang is a valuable language to learn for its efficiency, simplicity and strong concurrency support. Its popularity, ease of learning and robust ecosystem further solidify its appeal for individuals.
Go is a compiled language.
It is best suited for projects that require networking, web development and microservices features to complete.
Go is used for backend development because it is fast, scalable and supports efficient concurrent processing.
Go supports basic OOP concepts like structs and methods but does not use traditional classes.
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