Go Examples

Use the online live editor with Golang support. Edit and run the examples directly in your browser:

If you liked this project, you may also like
my golang-benchmarks repository:

my gotools repository:

my sql-examples repository:

my rp2040-examples repository:

or my rpi-examples repository:

About

These examples explain the basics of Golang. There will be more examples from time to time.

if you like, feel free to add more Golang examples. Many thanks to all contributors.

Install go(lang)

with homebrew:

Shell sudo brew install go

with apt-get:

Shell sudo apt-get install golang

install Golang manually or compile it yourself

Examples

The examples are divided into three levels of difficulty. The Beginner section contains very easy examples, starting with Hello World but also containing a few easy algorithms. The Advanced section uses more complicated features of Golang. Finally, the Expert section contains applications like telnet-clients or http-server (even with SSL). If you want even more Golang examples, you can take a look at my other go repositories at GitHub:

• golang-benchmarks shows how to benchmark the execution time of Golang functions
• GolangSortingVisualization visualizes various sorting algorithms on the terminal or as gif
• golang-minigames currently only contains a snake clone
• bbmandelbrot.go calculates a Mandelbrot Fractal and saves it as PNG
• golibs contains various Go packages (e.g. math, converter, stack, cli, ...)
• fsagent watch a folder for new or modified files and do something
• cgol.go is Conway's Game of Life in Golang
• micromarkdownGo converts markdown to html (via regular expression)
• wikiGo is a wiki software in Go
• WorkingTimeMeasurementSystem demonstrates how to create a simple time tracking system using Golang and SQLite
• zplgfa is an image converter to print pictures on zpl compatible labels
• ...

All of them are published as free and open source software.

If all of this is even not enough for you, you can take a look at the following websites:

• tour.golang.org
• Go by example
• Golang Book
• Go-Learn

Beginner

To execute a Golang program, write go run at the cli followed by the name of the file.
You also can convert the file to a binary executable program by the command go build.
If you know #!, also known as Shebang, there is an equivalent for go: //usr/bin/env go run $0 $@ ; exit

Print Hello World with comments (Golang Playground)

Shell go run HelloWorld.go

Print Hello World with comments (shebang version)

Shell ./HelloWorldShebang.go

Declare variables and print them (Golang Playground)

Shell go run var.go

Various ways (and styles) to print variables (Golang Playground)

Shell go run printf.go

If statement in Golang (Golang Playground)

Shell go run if.go Hello

Declare array and print its items (Golang Playground)

Shell go run array.go

Declare your own functions (Golang Playground)

Shell go run function.go

Do something multiple times (Golang Playground)

Shell go run for.go

Read via cli provided input data (Golang Playground)

Shell go run args.go string string2

Read via cli provided input data (Golang Playground)

Shell go run input.go

Or scan for it (Golang Playground)

Shell go run scan.go

Read named argument input data (Golang Playground)

Shell go run flag.go

Return the working directory (Golang Playground)

Shell go run dir.go

Return the current time/date in various formats (Golang Playground)

Shell go run time.go

Return pseudo random integer values (Golang Playground)

Shell go run random.go

Concat strings in two different ways (Golang Playground)

Shell go run cat.go

Modulo operation finds the remainder of division (Golang Playground)

Shell go run modulo.go

Split a string by another string and make an array from the result (Golang Playground)

Shell go run split.go

An example implementation of the Ackermann function (Golang Playground)

Shell go run ackermann.go

An example implementation of the Euclidean algorithm (Golang Playground)

Shell go run euklid.go

Submit a function as argument (Golang Playground)

Shell go run functioncallback.go

A function returned by a function (Golang Playground)

Shell go run functionclosure.go

A function with an unknown amount of inputs (variadic function) (Golang Playground)

Shell go run functionvariadic.go

Empty interface as argument (You Don't Know Type) (Golang Playground)

Shell go run interface.go

Execute Shell/Bash commands and print its output values (Golang Playground)

Shell go run shell.go

Make structs (objects) which have functions (Golang Playground)

Shell go run oop.go

Dependency injection for easier testing

Shell cd beginner/di go test

Hashing (md5, sha) in go (Golang Playground)

Shell go run hashing.go

Advanced

Benchmarking example (using JSON marshal and unmarshal for the sample) (Golang Playground) From the root directory ($GOPATH/github.com/SimonWaldherr/golang-examples), run this command:

Shell go test -bench=. -benchmem advanced/json_bench/main_test.go

Make pipe-able unix applications with os.Stdin (Golang Playground)

Shell go run pipe.go

AES-GCM encryption example (Golang Playground)

Shell go run aesgcm.go

Bcrypt hashing example (Golang Playground) Please install package golang.org/x/crypto/bcrypt before run this file by running go get golang.org/x/crypto/bcrypt

Shell go run bcrypt.go

Search element is exist in arrays or not (Golang Playground)

Shell go run in_array.go

Calculate triangles (Golang Playground)

Shell go run pythagoras.go (float|?) (float|?) (float|?)

Read from stdin (but don't wait for the enter key)

Shell go run getchar.go

Wait and sleep (Golang Playground)

Shell go run wait.go

Last in - first out - example (Pop and push in Golang) (Golang Playground)

Shell go run lifo.go

Split a string via regular expression and make an array from the result (Golang Playground)

Shell go run regex.go

More advanced regex (with time and dates) (Golang Playground)

Shell go run regex2.go

Use my golibs regex package and have fun (Golang Playground)

Shell go run regex3.go

Calculate and print the fibonacci numbers (Golang Playground)

Shell go run fibonacci.go

Calculate and print the requested (32th) prime number (Golang Playground)

Shell go run prime.go 32

Do things with numbers, strings and switch-cases (Golang Playground)

Shell go run numbers.go

Use a template to create and fill documents (this example uses LaTeX) (Golang Playground)

Shell go run template.go pdflatex -interaction=nonstopmode template_latex.tex

Start a ticker (do things periodically)

Shell go run ticker.go

Do something in case of a timeout (Golang Playground)

Shell go run timeout.go

Convert go object to json string (Golang Playground)

Shell go run json.go

Run unix/shell commands in go apps

Shell go run exec.go

Compress by pipe

Shell go run compress.go

Compress by file

Shell go run compress2.go

Parse CSV (Golang Playground)

Shell go run csv.go

Convert CSV to a Markdown table (Golang Playground)

Shell go run csv2md.go

Parse a XML string into a Struct with undefined Fields (Golang Playground)

Shell go run xml.go

Run a self killing app

Shell go run suicide.go

GoCV : hello video

Shell go run hello_video.go

GoCV : face detection

Shell go run face_detect.go 0 model/haarcascade_frontalface_default.xml

Run the example for generic (Golang Playground)

Shell go run generic.go

Expert

Calculate π with go (leibniz, euler and prime are running until you stop it via CTRL+C)

Shell go run pi2go.go leibniz go run pi2go.go euler go run pi2go.go prime

Calculate π with go - same as above - but with live output (based on gcurses)

Shell go run pi2go-live.go leibniz go run pi2go-live.go euler go run pi2go-live.go prime

List files in working directory

Shell go run explorer.go

run assembly code from golang

Shell go run assembly.go

run C code from golang

Shell go run cgo.go

generate Go code with golang templates

Shell go run codegen.go

Convert from rgb to hsl (Golang Playground)

Shell go run color.go

Telnet with Golang

Shell go run telnet.go

The smallest Golang http server

Shell go run httpd.go

Secure Golang http server

Shell go run httpsd.go

The smallest Golang http proxy

Shell go run proxy.go

Read and write cookies

Shell go run cookies.go

Demonstrate the power of multithreading / parallel computing you have to set GOMAXPROCS to something greater than 1 to see any effect

Shell export GOMAXPROCS=8 time go run parallel.go true time go run parallel.go false

A dynamic amount of channels

go time go run dynparallel.go 8

Run the compiler and comment each line which contains an error

Shell go build gocomment.go ./gocomment go-app.go

Convert a image to a grayscale and to a color inverted image

Shell go run image.go

Generate an image with three colored circles (with intersection)

Shell go run image2.go

Generate an image representing the Mandelbrot fractal

Shell go run image3.go

Sql (sqlite) Golang example
maybe you also wanna take a look at my sql-examples-project

Shell go run sqlite.go insert test go run sqlite.go select

Public-key/asymmetric cryptography signing and validating

Shell go run ppk-crypto.go

Command Line Arguments Golang Example We can get argument values though command line by specifying the operator '-' with the name of the argument and the value to be set. E.g. -env=qa

Shell go run command_line_arguments.go go run command_line_arguments.go -env=qa -consumer=true

Cron Golang Example We can trigger a function at a particular time through cron

Shell go run cron.go

Map Golang Example Hash Map standard functions in golang

Shell go run map.go

TinyGo

You can even use Go on microcontrollers, the keyword here is TinyGo, a go compiler specially developed for SBCs and MCUs.
If you want to blink the LED of your Raspberry Pi Pico, try this:

Shell tinygo build -o firmware.uf2 -target=pico ./tinygo/blink.go

and then upload it to the pico.

Compile

One great aspect of Golang is, that you can start go applications via go run name.go, but also compile it to an executable with go build name.go. After that you can start the compiled version which starts much faster. If you start fibonacci.go and the compiled version you will notice, that the last line which contains the execution time doesn't differ much, but if you start it with time ./fibonacci 32 and time go run ./fibonacci.go 32 you will see the difference.

License

Copyright © 2024 Simon Waldherr Dual-licensed. See the LICENSE file for details.