计时器在Golang中的工作方式[重复]

I'm trying to undersand channels in Go. There is a simple code

package main

import (
    "fmt"
    "sync"
    "time"
)

func main() {
    var wg sync.WaitGroup
    wg.Add(1)

    go func() {
        defer wg.Done()

        i := 0

        for {
            select {
            case <-time.After(3 * time.Second):
                fmt.Println("EXIT: 3 seconds")
                return
            case <-time.After(1 * time.Second):
                fmt.Println(i, "second")
        }
        i++
    }
}()

wg.Wait()
}

I expect console result like this

0 second
1 second
2 second
EXIT: 3 seconds

But actually it is like this

0 second
1 second
2 second
3 second
4 second
5 second
6 second
...

What am I missing with this timer and how can I fix a problem?

</div>

It's because of for loop. Each circle of loop RightHandSide of case <-time.After(3 * time.Second): in select statement evaluated and give you fresh timer. For example this way things should work

stop := time.After(3 * time.Second)
for {
    select {
        case <-stop:
            fmt.Println("EXIT: 3 seconds")
            return
        case <-time.After(1 * time.Second):
            fmt.Println(i, "second")
    }
}