Go

Go is a general-purpose language designed with systems programming in mind. It was initially developed at Google in the year 2007 by Robert Griesemer, Rob Pike, and Ken Thompson. It is strongly and statically typed, provides inbuilt support for garbage collection, and supports concurrent programming.

Programs are constructed using packages, for efficient management of dependencies. Go programming implementations use a traditional compile and link model to generate executable binaries. The Go programming language was announced in November 2009 and is used in some of the Google's production systems.

First Program

package main
import ("fmt")

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

Rest API

package main

import (
    "net/http"

    "github.com/gin-gonic/gin"
)

// album represents data about a record album.
type album struct {
    ID     string  `json:"id"`
    Title  string  `json:"title"`
    Artist string  `json:"artist"`
    Price  float64 `json:"price"`
}

// albums slice to seed record album data.
var albums = []album{
    {ID: "1", Title: "Blue Train", Artist: "John Coltrane", Price: 56.99},
    {ID: "2", Title: "Jeru", Artist: "Gerry Mulligan", Price: 17.99},
    {ID: "3", Title: "Sarah Vaughan and Clifford Brown", Artist: "Sarah Vaughan", Price: 39.99},
}

func main() {
    router := gin.Default()
    router.GET("/albums", getAlbums)

    router.Run("localhost:8080")
}

// getAlbums responds with the list of all albums as JSON.
func getAlbums(c *gin.Context) {
    c.IndentedJSON(http.StatusOK, albums)
}

Rest API full code

package main

import (
    "net/http"

    "github.com/gin-gonic/gin"
)

// album represents data about a record album.
type album struct {
    ID     string  `json:"id"`
    Title  string  `json:"title"`
    Artist string  `json:"artist"`
    Price  float64 `json:"price"`
}

// albums slice to seed record album data.
var albums = []album{
    {ID: "1", Title: "Blue Train", Artist: "John Coltrane", Price: 56.99},
    {ID: "2", Title: "Jeru", Artist: "Gerry Mulligan", Price: 17.99},
    {ID: "3", Title: "Sarah Vaughan and Clifford Brown", Artist: "Sarah Vaughan", Price: 39.99},
}

func main() {
    router := gin.Default()
    router.GET("/albums", getAlbums)
    router.GET("/albums/:id", getAlbumByID)
    router.POST("/albums", postAlbums)

    router.Run("localhost:8080")
}

// getAlbums responds with the list of all albums as JSON.
func getAlbums(c *gin.Context) {
    c.IndentedJSON(http.StatusOK, albums)
}

// postAlbums adds an album from JSON received in the request body.
func postAlbums(c *gin.Context) {
    var newAlbum album

    // Call BindJSON to bind the received JSON to
    // newAlbum.
    if err := c.BindJSON(&newAlbum); err != nil {
        return
    }

    // Add the new album to the slice.
    albums = append(albums, newAlbum)
    c.IndentedJSON(http.StatusCreated, newAlbum)
}

// getAlbumByID locates the album whose ID value matches the id
// parameter sent by the client, then returns that album as a response.
func getAlbumByID(c *gin.Context) {
    id := c.Param("id")

    // Loop through the list of albums, looking for
    // an album whose ID value matches the parameter.
    for _, a := range albums {
        if a.ID == id {
            c.IndentedJSON(http.StatusOK, a)
            return
        }
    }
    c.IndentedJSON(http.StatusNotFound, gin.H{"message": "album not found"})
}