https://github.com/hacksu/intro_to_go
Learning the basics of Go with a basic shopping application
https://github.com/hacksu/intro_to_go
advanced lesson
Last synced: 7 months ago
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Learning the basics of Go with a basic shopping application
- Host: GitHub
- URL: https://github.com/hacksu/intro_to_go
- Owner: hacksu
- Created: 2019-10-14T19:14:19.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2019-10-15T16:46:19.000Z (over 6 years ago)
- Last Synced: 2024-04-09T21:54:52.548Z (almost 2 years ago)
- Topics: advanced, lesson
- Language: Go
- Size: 3.91 KB
- Stars: 0
- Watchers: 7
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
# intro_to_go
The aim of this lesson is to cover the basics of the Go programming language
Some important things to know about Go:
* It was designed at Google by Robert Griesemer, Rob Pike, and Ken Thompson
* Syntactically similar to C
* It is not exactly an object oriented language
* No classes, but there are structures
* You can define methods for these structures
* Still similar to OOP
* [How to write Go code](https://golang.org/doc/code.html)
* The `go` tool requires you to organize your code in a specific way
* We will cover the basics in this lesson, but use this for further reading or as a reference
## Getting started
First, head to [the official Go website](https://golang.org/) and download the latest version of Go
I would recommend using VS Code with the Go extension for development. That is what we'll be using in this lesson.
* We will compile and run Go in the command line
* There is a Go IDE, GoLand by JetBrains, as well if you are interested (but we won't be really covering that)
## Your first Go program
Open up the command line, and navigate to your Go workspace:
* `C:\Users\YourName\go\src` on Windows
* `$HOME/go/src` on Unix based systems
* The location of your workspace can be changed. See "How to write Go code" above
Make a new directory (folder) called `shopping`
Navigate into `shopping` and create a file called `main.go`. We will write the following code
```go
package main
import (
"fmt"
)
func main() {
fmt.Println("Wow I did it")
}
```
To run this, type `go run main.go` into the command line
Congrats, you've written your first Go program!
## Getting some input
An important part of this application is reading in user input, so we'll learn about that next
```go
package main
import (
"fmt"
)
func main() {
fmt.Println("What is your name?")
var name string
fmt.Scanln(&name)
fmt.Println("Hello,", name)
}
```
Again, type `go run main.go` into the command line to run this
## Adding some structures
Now that basic I/O has been covered, let's move on to structures
Here's a basic structure that we're going to be using:
```go
type product struct {
name string
cost int
}
```
Now we can create a new product:
```go
func main() {
p := product{
name: "Brick",
cost: 10,
}
fmt.Println(p.name, "costs $", p.cost)
}
```
Using structs, we can begin to build a more complex application
## Creating the store
We're going to start building our store application
```go
func main() {
brick := product{name: "brick", cost: 10}
corn := product{name: "corn", cost: 6}
gamecube := product{name: "gamecube", cost: 100}
inventory := []product{brick, corn, gamecube}
fmt.Println("Welcome to the store!")
fmt.Println("Options:")
fmt.Println("(i)nventory")
fmt.Println("(b)uy item")
fmt.Println("(a)dd item")
fmt.Println("(q)uit")
var choice string
fmt.Scanln(&choice)
for choice != "q" {
switch choice {
case "i":
for _, p := range inventory {
fmt.Println("name:", p.name)
fmt.Println("cost:", p.cost)
fmt.Println()
}
break
case "b":
var toBuy string
fmt.Print("What product would you like to buy? ")
fmt.Scanln(&toBuy)
loc := -1
for i, p := range inventory {
if p.name == toBuy {
loc = i
}
}
if loc == -1 {
fmt.Println("Item isn't in stock")
} else {
inventory = append(inventory[:loc], inventory[loc+1:]...)
}
break
case "a":
var newName string
fmt.Print("Enter a product name: ")
fmt.Scanln(&newName)
var newCost int
fmt.Print("Enter a cost: ")
fmt.Scanf("%d", &newCost)
inventory = append(inventory, product{name: newName, cost: newCost})
break
}
fmt.Println("Welcome to the store!")
fmt.Println("Options:")
fmt.Println("(i)nventory")
fmt.Println("(b)uy item")
fmt.Println("(a)dd item")
fmt.Println("(q)uit")
fmt.Scanln(&choice)
}
}
```
The completed code can also be found in the `main.go` file in this repository
## Further reading
If you are interested in learning more about Go, I would recommend checking out these resources:
* [A Tour of Go](https://tour.golang.org)
* [Go by Example](https://gobyexample.com/)
Another great resource in the official docs for when you're more familiar with the language:
* [Effective Go](https://golang.org/doc/effective_go.html)