Go Language

What is Go (Golang)?

• A programming language designed at Google
• A static typing language
• Simple syntax similar to C language
• Memory safe, garage collection, structural typing (like a duck typing), concurrency
• Rich standard libraries

What are applications of Golang?

• System programming (alternatives to C/C++)
• Backend servers

Notice

• This lecture provides fundamental codes that are needed for TDD (Test-Driven Development) with Golang.
• We skip the detailed syntax of Golang (Google it! or ask to ChatGPT).

Hello World

Project Initialization

Start by creating a new project directory and initializing a Go module:

mkdir hello
cd hello
go mod init hello

• mkdir hello: Create a new directory named hello.
• cd hello: Change into the hello directory.
• go mod init hello: Initialize a new Go module named hello. This creates a go.mod file that defines the module's name and its dependencies.
• Note: Visual Studio Code opens the current directory as a workspace, so you can open the hello directory in VS Code.

Write a code for Hello World

• Create a file hello.go

package main

import "fmt"

func main() {
    fmt.Println("Hello world")
}

• Execute the following command in Terminal

go run hello.go

• Output

$ go run hello.go
Hello world

Explanation

• package main and main function are required for the entry point of program execution (same as main function of C language). The main function should be placed in main package.
• import declares what libraries (packages) are used in the code.
  • fmt is a library for formatting and printing
• fmt.Println indicates the function Println in the library fmt.There is no way to omit the name of library, i.e., fmt.Println cannot be written by Println.
• go run provides an execution of code similar to a script language, but it involves both compiling and executing.
  • go build: the command for compiling

A minimum checklist: To write codes with Golang

This is a minimum checklist to learn Golang. Ask ChatGPT or Google for more details.

• Check the fundamental types of Golang; int, float64, string
• Check the declaration of variables; the usage of var and :=
• Check the slice and its methods
• Check the type definition and the structure; type
• Check the declaration of methods for a type; methods, receiver and pointer receiver

Summary

• Go is a programming language designed at Google, known for its simplicity and efficiency.
• It is statically typed, memory safe, and has a rich standard library.
• The lecture provides a basic introduction to Go, focusing on the "Hello World" program and essential concepts.
• Students are encouraged to explore more about Go's syntax and features through online resources or ChatGPT.