switch case 中的 break 语句在无限循环中不起作用

Question

在下面的代码中，我无法理解为什么 default 中的 break 语句不足以结束无限循环。 PlayGroundLink

package main

import "fmt"

func main() {
    for { //infinite loop
        fmt.Print("Enter Choice")
        userChoice := 3 //Intenssionaly given value here for testing
        switch userChoice {
        case 1:
            fmt.Println("Enter Radios of Circle:")
        case 2:
            fmt.Println("Enter Radios of Circle:")
        default:
            fmt.Println("\nExiting...")
            break  // this break is executing , but why it is not coming out of infinte 'for' loop ?
        }

    }
}

以上代码的输出（未结束..继续）

Enter Choice
Exiting...
Enter Choice
Exiting...
Enter Choice
Exiting...
Enter Choice
Exiting...
Enter Choice
Exiting...
Enter Choice
Exiting...
Enter Choice
Exiting...
Enter Choice
Exiting...

Answer 1

如果您在循环中添加标签，则可以从循环中显式 break：

package main

import "fmt"

func main() {
    Loop:
        for { //infinite loop
            fmt.Print("Enter Choice")
            userChoice := 3 //Intenssionaly given value here for testing
            switch userChoice {
            case 1:
                fmt.Println("Enter Radios of Circle:")
            case 2:
                fmt.Println("Enter Radios of Circle:")
            default:
                fmt.Println("\nExiting...")
                break Loop
            }

        }
    fmt.Println("Outside the loop!")
}

这里是a working example

switch case 中的 break 语句在无限循环中不起作用

break statement inside switch case don't have effect in infinite loop

infinite-loop

go