Go语言实战案例

1. 实现一个简易的猜数字游戏

bufio的主要作用是减少I/O操作的次数，提供读写性能。其工作原理是通过在内存中维护一个缓冲区，先将数据读入缓冲区，再从缓冲区中读取数据，从而减少对底层I/O设备的访问次数。

package main

import (
	"bufio"
	"fmt"
	"math/rand"
	"os"
	"strconv"
	"strings"
	"time"
)

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

	reader := bufio.NewReader(os.Stdin)
	for {
		input, err := reader.ReadString('\n')
		if err != nil {
			fmt.Println("error....", err)
			return
		}
		input = strings.TrimSuffix(input, "\n")

		guess, err := strconv.Atoi(input)
		if err != nil {
			fmt.Println("invaild input", err)
			return
		}
		fmt.Println("your guess is ", guess)

		if guess > secretNum {
			fmt.Println("your guess is bigger than secretNum")

		} else if guess < secretNum {
			fmt.Println("your guess is smaller than secretNum")
		} else {
			fmt.Println("you win!")
		}
	}

}

2. 用fmt.Scanf 优化代码

在Go语言中，fmt.Scanf函数用于从标准输入中读取格式化的输入。这个函数类似于C语言中的scanf函数，它按照指定的格式读取输入，并将读取的值存储到提供的变量中。

package main

import (
	"fmt"
	"math/rand"
	"time"
)

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

	for {
		var guess int
		fmt.Print("Enter your guess (0-99): ")
		_, err := fmt.Scanf("%d", &guess)
		if err != nil {
			fmt.Println("Invalid input, please enter an integer. Error:", err)
			continue
		}
		fmt.Println("Your guess is", guess)

		if guess > secretNum {
			fmt.Println("Your guess is bigger than secretNum")
		} else if guess < secretNum {
			fmt.Println("Your guess is smaller than secretNum")
		} else {
			fmt.Println("You win!")
			break
		}
	}
}