golang building tutorial

Go language (also known as Golang) is a programming language developed by Google. It has a certain degree of readability and simplicity. It is also very suitable for writing high-concurrency and large-volume web applications. With the continuous development of Golang, more and more developers have begun to actively learn and use this language. Here is a tutorial on how to build Golang.

1. Installing Golang

First you need to install the Golang environment. The Golang official website provides download addresses for various operating systems. Choose the version that suits your operating system to download https:/ /golang.org/dl/.

After the installation is completed, you can enter the following command on the command line to check whether the installation is successful:

go version

If the version number appears, the installation is successful.

2. Set Golang environment variables

Then you need to set the Golang environment variables. Open the terminal or command line tool and enter the following command to set the environment variables:

export GOPATH=$HOME/go
export PATH=$PATH:/usr/local/go/bin:$GOPATH/bin

Where$HOME/go is the default working folder of the Go project, which can be changed according to your own needs.

3. Create a HelloWorld program

As soon as the Golang environment is installed and configured, we can start writing the first program:

package main

import "fmt"

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

In the command line Go into the directory and enter the following command to compile and run the program:

go build
./helloworld

If all goes well, you will see the output on the screen: Hello, World!

This program is very simple, but it Demonstrates what a basic Go language program should look like. Among them, package declares which package this program belongs to, and import declares the required dependency packages, followed by the main() function, which is the entry point of the program. , and finally just one line of output statement.

4. Developing Web Applications using Go

The following is a simple Golang web application that listens to the local 8080 port and displays "Hello world" in the browser !":

package main

import (
    "fmt"
    "net/http"
)

func main() {
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprint(w, "Hello world!")
    })

    http.ListenAndServe(":8080", nil)
}

The above code uses a total of two functions - http.HandleFunc() and http.ListenAndServe().

http.HandleFunc() is used to set the route (URL path) and response function. As in the above code, "/" is the defined route, and the function part is the response we want to return. content.

http.ListenAndServe() is used to listen to the specified port and perform routing. For example, the port 8080 is specified in the above code.

Start the program and access http://localhost:8080 through the browser. You can see the output of "Hello, world!", which means that the web application is running normally.

5. Develop RESTful API using Golang

RESTful API is a popular architectural style in modern web development, and Golang also provides good support. The following is a simple sample program:

package main

import (
    "encoding/json"
    "log"
    "net/http"
)

type User struct {
    Name string `json:"name"`
    Age  int    `json:"age"`
}

var users []*User

func createUser(w http.ResponseWriter, r *http.Request) {
    var user User

    err := json.NewDecoder(r.Body).Decode(&user)
    if err != nil {
        http.Error(w, err.Error(), http.StatusBadRequest)
        return
    }

    users = append(users, &user)
    w.WriteHeader(http.StatusOK)
    return
}

func getUsers(w http.ResponseWriter, r *http.Request) {
    w.Header().Set("Content-Type", "application/json")
    json.NewEncoder(w).Encode(users)
    return
}

func main() {
    http.HandleFunc("/user", createUser)
    http.HandleFunc("/users", getUsers)

    log.Fatal(http.ListenAndServe(":8080", nil))
}

The above code sets both /users and /user through the http.HandleFunc() function A route that uses json to parse and generate JSON data, making data transmission more convenient and readable.

The browser or other client requests http://localhost:8080/users to get all the user information created. This is a simple RESTful API.

Summary

The Golang language can be used to develop various types of programs, including web applications, tools, back-end services, etc. Learning the Golang language can help you quickly master the essence of the development language, and can also provide better support for learning other development languages.

The above is a tutorial on how to build Golang. I believe these contents can be helpful to Golang beginners.

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