问题描述
我想要一组代码被执行，直到用户显式地想要退出该函数。例如：当用户运行该程序时，他将看到2个选项：
I want a set of code to be executed until user explicitly wants to exit the function. For eg: when a user runs the program, he will see 2 options:
- 再次运行
- 退出
这将使用开关盒结构来实现。这里如果用户按下1，则与1关联的功能集将执行，如果用户按下2，程序将退出。我应该如何在golang中实现这个场景？在java中，我相信这可以通过do while结构来完成，但不支持while循环。以下是我尝试过的代码，但是这个代码在无限循环中：
this will be achieved using switch case structure. Here if user presses 1, set of functions associated with 1 will execute and if user presses 2, the program will exit. How should i achieve this scenario in golang ? In java, i believe this could be done using do while structure but go doesn't support do while loop. Following is my code which i tried but this goes in a infinite loop:
func sample() {
var i = 1
for i > 0 {
fmt.Println("Press 1 to run")
fmt.Println("Press 2 to exit")
var input string
inpt, _ := fmt.Scanln(&input)
switch inpt {
case 1:
fmt.Println("hi")
case 2:
os.Exit(2)
default:
fmt.Println("def")
}
}
}
不管输入如何，程序只打印hi。有人可以请我改正我在这里做了什么错误吗？
The program irrespective of the input, prints only "hi". Could someone please correct me what wrong i am doing here ?
谢谢。
推荐答案
当这个问题被问及时，这是针对这个特定场景的更好的答案（我很少知道这是在Google搜索do while loop golang时得到的＃1结果）。为了回答这个问题，请参阅。
When this question was asked this was a better answer for this specific scenario (little did I know this would be the #1 result when searching Google for "do while loop golang"). For answering this question generically please see @LinearZoetrope's answer below.
将你的函数封装在for循环中：
Wrap your function in a for loop:
package main
import (
"fmt"
"os"
)
func main() {
fmt.Println("Press 1 to run")
fmt.Println("Press 2 to exit")
for {
sample()
}
}
func sample() {
var input int
n, err := fmt.Scanln(&input)
if n < 1 || err != nil {
fmt.Println("invalid input")
return
}
switch input {
case 1:
fmt.Println("hi")
case 2:
os.Exit(2)
default:
fmt.Println("def")
}
}
没有任何声明的循环相当于一个，而其他类似C语言的循环。查看，其中涵盖 code>循环。
A for loop without any declarations is equivalent to a while loop in other C-like languages. Check out the Effective Go documentation which covers the for loop.
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