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Setting up Go Environment🔗

Download and Install from here : https://go.dev/dl/

For mac we can use brew as well : brew install go or for windows choco install go.

Check if installed correctly : go version

Hello World in Go🔗

Making a Go Module🔗

mkdir ch1
cd ch1
# marking the dir as go module
go mod init hello_world
cat go.mod
  • above command creates a go module file : go.mod which is exact specification of dependencies of code within the module.

Building the Go File🔗

  • create a hello.go file with following content (ignore the indentation)
package main

import "fmt"

func main() {
fmt.Println("Hello, world!")
}
  • first line is a package declaration, the main package in a Go module contains code that starts a Go program.
  • Next is import of formatting library in go that is used to print to console.
  • all go programs start from main function in the main package
go build
# this creates a binary : hello_world (same as module declaration)
./hello_world   # Hello, World!
# building binary with different name
go build -o hello
./hello
  • go fmt is a important tool and language designers spent time considering the code formatting. Go doesn’t give a lot of flexibility in terms of formatting.
  • Go enforces to use tabs to indents and if opening brace is not in same line as declaration or command that begins the block.
  • fixing the whitespaces in your code to made go standards : go fmt ./... (applies to all files)

NOTE:

  • go fmt doesn’t fix braces on wrong line because of semicolon insertion rule (look it up)

go vet🔗

go vet detects is whether a value exists for every placeholder in a formatting template. Example : template ("Hello, %s!\n") with a %s placeholder, but no value assigned to it

Using Makefiles to Automate builds🔗

  • each possible operation is called a target, .DEFAULT_GOAL defines default target to run.
  • .PHONY keeps make from getting confused if a directory or file has same name as one of the listed targets.
.DEFAULT_GOAL := build

.PHONY:fmt vet build
fmt:
    go fmt ./...

vet: fmt
    go vet ./...

build: vet
    go build
  • Now running one command make does all three tasks for us
  • Great Tutorial on Makefile : https://makefiletutorial.com/

Go Compatibility Promise🔗

  • go development tools are periodically updated roughly every 6 months, go team commits for backward compatibility.
  • See
    • https://go.dev/doc/go1compat
    • https://www.youtube.com/watch?v=v24wrd3RwGo

Staying up to Date🔗

  • brew upgrade go