Go basics

Go es el lenguaje de programación de Google lanzado en 2009, este está disponible para diferentes tipos de sistemas Unix-like, incluidos FreeBSD, Linux, Mac OS X y Plan 9 además de para distintas arquitecturas como i386, amd64 y ARM.
Las principales ventajas respecto a otros lenguajes de programacón son:

Mayor rendimiento que Python, Ruby o JavaScript.
Mejor soporte para trabajos concurrentes.
Go runtime incluído en los binarios lo que lo hace altamente distribuíble entre sistemas.
Librerías descentralizadas, cada programador hospeda su código donde desee, para instalar el software se accede a dicha plataforma directamente.

- Instalación
- Hello world
- Variables y tipos de datos
- Estructuras de control de flujo
- Funciones
- Arrays y slices
- Maps
- Recursos adicionales

Instalación:

pkg install go

Hello world:

vi 00-HelloWorld.go

// Define as executable programme not a library.
package main

// Format library
import "fmt"

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

go run 00-HelloWorld.go

Hello world!

go build 00-HelloWorld.go

file 00-HelloWorld

00-HelloWorld: ELF 64-bit LSB executable, x86-64, version 1 (FreeBSD), statically linked, for FreeBSD 12.3, FreeBSD-style, Go BuildID=Y4MQLyWJvSerAP4BVk2v/9P2KHgW0r9hY_WmEb9uy/zyzxSbQ1ETRoacqPL2Kq/-SzOfM95EQBcBz8mFnZr, with debug_info, not stripped

./00-HelloWorld

Hello world!

Variables y tipos de datos:

vi 01-Variables.go

// Define as executable programme not a library.
package main

// Format library
import "fmt"

func main() {
    // Variable declaration
    var x int
    x = 5

    // Short declaration method, auto variable type detection
    y := 10

    // Imprimir variables
    fmt.Println("x:", x)
    fmt.Println("y:", y)
}

go run 01-Variables.go

x: 5
y: 10

Estructuras de control de flujo:

vi 02-FlowControl.go

// Define as executable programme not a library.
package main

// Format library
import "fmt"

func main() {
    // Conditionals
    age := 25
    if age >= 18 {
        fmt.Println("You are on legal age")
    } else {
        fmt.Println("You are NOT on legal age")
    }

    // For loop
    for i := 0; i < 5; i++ {
        fmt.Println(i)
    }
}

go run 02-FlowControl.go

You are on legal age
0
1
2
3
4

Funciones:

vi 03-Functions.go

// Define as executable programme not a library.
package main

// Format library
import "fmt"

// Function that adds two numbers
func add(a, b int) int {
    return a + b
}

func main() {
    result := add(3, 4)
    fmt.Println("Result:", result)
}

go run 03-Functions.go

Result: 7

Arrays y slices:

vi 04-Arrays_Slices.go

// Define as executable programme not a library.
package main

// Format library
import "fmt"

func main() {
    // Array
    var numbers [5]int
    numbers[0] = 1
    numbers[1] = 2
    numbers[2] = 3
    numbers[3] = 4
    numbers[4] = 5

    // Slice: We generate an array with the sub-content of another array
    // From position: numbers[1] to numbers[4-1], the last position is not included
    slice := numbers[1:4]

    fmt.Println("Array:", numbers)
    fmt.Println("Slice:", slice)
}

go run 04-Arrays_Slices.go

Array: [1 2 3 4 5]
Slice: [2 3 4]

Maps:

vi 05-Maps.go

// Define as executable programme not a library.
package main

// Format library
import "fmt"

func main() {
    // Map declaration
    person := map[string]string{
        "name":    "John",
        "surname": "Doe",
        "age":     "30",
    }

    fmt.Println("Name:", person["name"])

    // Add map field
    person["city"] = "New York"

    // Print the map
    fmt.Println("Person:", person)
}

go run 05-Maps.go

Name: John
Person: map[age:30 city:New York name:John surname:Doe]

Recursos adicionales:

GoByExample