Go语言 - 基础

1.什么是Go语言

高性能、高并发

语法简单

标准库丰富

静态编译，占用空间小

快速编译

跨平台

垃圾回收

2.语法特性

变量与常量声明可以不声明类型，编译器隐式判断

if条件语句不加括号，执行语句必须加大括号

没有while，用for替代

switch的case默认自带break，switch条件语句可以为空

支持切片以及切片操作

range快速遍历索引与值

变量类型后置

使用指针来实现引用传递

定义函数时，函数名前指定结构体等对象可以实现接口功能

字符串支持 ‘+’ 拼接

值相等可以用 ‘=’ 判断

 字符串一些操作：

	a := "hello"
	fmt.Println(strings.Contains(a, "ll"))                // true
	fmt.Println(strings.Count(a, "l"))                    // 2
	fmt.Println(strings.HasPrefix(a, "he"))               // true
	fmt.Println(strings.HasSuffix(a, "llo"))              // true
	fmt.Println(strings.Index(a, "ll"))                   // 2
	fmt.Println(strings.Join([]string{"he", "llo"}, "-")) // he-llo
	fmt.Println(strings.Repeat(a, 2))                     // hellohello
	fmt.Println(strings.Replace(a, "e", "E", -1))         // hEllo
	fmt.Println(strings.Split("a-b-c", "-"))              // [a b c]
	fmt.Println(strings.ToLower(a))                       // hello
	fmt.Println(strings.ToUpper(a))                       // HELLO
	fmt.Println(len(a))                                   // 5
	b := "你好"
	fmt.Println(len(b)) // 6

结构体字段大写，即可marshal序列化

3.实战

3.1猜数字游戏

首先生成答案

    maxNum := 100
	rand.Seed(time.Now().UnixNano())
	secretNumber := rand.Intn(maxNum)
	fmt.Println("The secret number is ", secretNumber)

用流的方式读取用户输入

    fmt.Println("Please input your guess")
	reader := bufio.NewReader(os.Stdin)
	input, err := reader.ReadString('n')
	if err != nil {
		fmt.Println("An error occured while reading input. Please try again", err)
		return
	}
	input = strings.TrimSuffix(input, "rn")

	guess, err := strconv.Atoi(input)
	if err != nil {
		fmt.Println("Invalid input. Please enter an integer value")
		return
	}
	fmt.Println("You guess is", guess)

循环执行直到猜对为止

func main() {
	maxNum := 100
	rand.Seed(time.Now().UnixNano())
	secretNumber := rand.Intn(maxNum)
	// fmt.Println("The secret number is ", secretNumber)

	fmt.Println("Please input your guess")
	reader := bufio.NewReader(os.Stdin)
	for {
		input, err := reader.ReadString('n')
		if err != nil {
			fmt.Println("An error occured while reading input. Please try again", err)
			continue
		}
		input = strings.TrimSuffix(input, "rn")

		guess, err := strconv.Atoi(input)
		if err != nil {
			fmt.Println("Invalid input. Please enter an integer value")
			continue
		}
		fmt.Println("You guess is", guess)
		if guess > secretNumber {
			fmt.Println("Your guess is bigger than the secret number. Please try again")
		} else if guess < secretNumber {
			fmt.Println("Your guess is smaller than the secret number. Please try again")
		} else {
			fmt.Println("Correct, you Legend!")
			break
		}
	}
}

3.2 在线词典（调用api,解析json）

生成请求

彩云小译，键入单词并翻译，F12，network, name下拉至dict, copy as curl(bash)

打开Convert curl commands to code

func main() {
	client := &http.Client{}
	var data = strings.NewReader(`{"trans_type":"en2zh","source":"good"}`)
	req, err := http.NewRequest("POST", "https://api.interpreter.caiyunai.com/v1/dict", data)
	if err != nil {
		log.Fatal(err)
	}
	req.Header.Set("Connection", "keep-alive")
	req.Header.Set("DNT", "1")
	req.Header.Set("os-version", "")
	req.Header.Set("sec-ch-ua-mobile", "?0")
	req.Header.Set("User-Agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.51 Safari/537.36")
	req.Header.Set("app-name", "xy")
	req.Header.Set("Content-Type", "application/json;charset=UTF-8")
	req.Header.Set("Accept", "application/json, text/plain, */*")
	req.Header.Set("device-id", "")
	req.Header.Set("os-type", "web")
	req.Header.Set("X-Authorization", "token:qgemv4jr1y38jyq6vhvi")
	req.Header.Set("Origin", "https://fanyi.caiyunapp.com")
	req.Header.Set("Sec-Fetch-Site", "cross-site")
	req.Header.Set("Sec-Fetch-Mode", "cors")
	req.Header.Set("Sec-Fetch-Dest", "empty")
	req.Header.Set("Referer", "https://fanyi.caiyunapp.com/")
	req.Header.Set("Accept-Language", "zh-CN,zh;q=0.9")
	req.Header.Set("Cookie", "_ym_uid=16456948721020430059; _ym_d=1645694872")
	resp, err := client.Do(req)
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	bodyText, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%sn", bodyText)
}

json解析response body

copy response 键入JSON转Golang Struct - 在线工具 - OKTools

转换嵌套即可