Welcome to Go

Go or Golang is a static, inferred, structural programming language created by Robert Griesemer, Rob Pike, and Ken Thompson initially at Google. It has built-in support for concurrency, testing, and has rich standard library.

Go is extremely easy to dive into. There are a minimal number of fundamental language concepts and the syntax is clean and designed to be clear and unambiguous. - Dave Astels.

Install Go

Let’s first install the Golang. You can find the release binary from the official download page and instructions in the official installation guide.

As I’m using GNU/Linux system, I need to follow these steps. The steps for the GNU/Linux are written so clearly that I follow these steps even I want to install something else from given .tar.gz file.

# unzip the .tar.gz file at /usr/local
tar -C /usr/local -xzf go1.24.1.linux-amd64.tar.gz
# Add the bin path to access go command
export PATH=$PATH:/usr/local/go/bin
# Test
go version

Let’s write the hello, world program. Create a file with name hello.go and write the following code.

package main

import "fmt"

func main() {
    fmt.Println("hello, world")
}

Run the following command in the terminal to run this program.

go run hello.go
hello, world

Explanation of the hello, world Program

  1. You can package your code by any name you want to arrange your code logically. But, package main is the special package that should contain main() function. We’ll talk about package stuff in future if it looks confusing to you. For now, just add package main at the top of the file. We we write something else as name of the package than main, you’ll know the meaning of it.
  2. import is used to import the library or package. Here, we are importing fmt standard library to access the Println() function.
  3. Execution of the program starts from main() function. func keyword is used to define function.
  4. Println() function is used to print text in the terminal. Println() is part of fmt. Remember that P is capital in Println() function.

Variables

There are multiple ways to define variables and assign values to them. As Go is static programming language, type is bound to the variable than the value. What value a variable can accept is depends on type it bound to.

To define a variable following syntax is used. var keyword, followed by name of the variable, and finally the type of the variable.

var x int

As the type of x is int, it can only accept valid integer values. Assigning floating number of string results in error.

Boring = or assignment operator is used to assign value to the variable.

var x int = 42

If you are assigning the value to the variable at the time of defining it, you can drop the type from the syntax as Go will inter the type based on initial value.

var x = 42

Even further, replace boring = with interesting := operator and you don’t have to write var keyword.

x := 42

And now you know couple of ways to define variable in Go. Use the syntax that make more sense to you in terms of program context and usage.

Go is rich in types. Following are some the basic data types Go has supports for.

bool

string

int  int8  int16  int32  int64
uint uint8 uint16 uint32 uint64 uintptr

byte // alias for uint8

rune // alias for int32
     // represents a Unicode code point

float32 float64

complex64 complex128

nil

You don’t have to remember all these types! You’ll get to know and use these types as you get more experience with Go.

Here is an example program that demonstrate the usage of some of the types from above list.

package main

import "fmt"

func main() {
    var name string = "Peter"           // String
    var age int = 32                    // Integer
    var height float64 = 190.47         // Float64
    var adult bool = true               // Boolean
    var address *string = nil           // Nil pointer

    fmt.Println(name, age, height, adult, address)
}

Output is:

Peter 32 190.47 true <nil>

In Go, variables can be reassigned and are mutable by default. Unlike current tend, Go doesn’t enforce immutability by default.

age := 32
age = 42

fmt.Println(age)

Output is:

42

In Go, if you declare a variable but don’t use it, the compiler will give an error. To ignore values and fix the compiler error, use the blank identifier _:

_ = 12
result := 12 + 10
_ = result // If you're not going to use result

String Interpolation and Concatenation

Go uses the fmt package for string formatting and the + operator for concatenation. Go use Printf() function with format specifier to do the string interpolation.

package main

import "fmt"

func main() {
    name := "Bruce"
    age  := 32

    fmt.Printf("I am %s and %d years old\n", name, age)
    fmt.Println("But my real name is " + "Batman 🦇")
}

Output is:

I am Bruce and 32 years old
But my real name is Batman 🦇

Finally, following are the list of popular projects created in Golang.

  1. Kubernetes
  2. Docker
  3. Prometheus
  4. Micro Editor
  5. Grafana
  6. CockroachDB

Acknowledgement: This article is heavily inspired by content from RunElixir.com.

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· Tags: go