16. channel和range,select

channel和range

package main
import "fmt"
func main() {
    c:= make(chan int)
    go func() {
        for i:=0;i<3;i++{
            c<-i
        }
        // 当不需要再次发送数据后需要关闭channel,如果被关闭可能会引发死锁
        close(c)
    }()
    // range 会阻塞等待
    for num := range c{
        fmt.Println(num)
    }
}

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channel和select

• select用来监视多个channel状态

package main
import "fmt"
func yield(c,quit chan int)  {
    temp:=2
    for  {
        select {
        case c<-temp:
            temp*=2
        case <-quit:
            return
        }
    }
}
func main() {
    c :=make(chan int)
    quit :=make(chan int)
    go func() {
        for i:=0;i<10;i++ {
            fmt.Println(<-c)
        }
        quit<-0
    }()
    yield(c,quit)
}

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