57 lines
972 B
Go
57 lines
972 B
Go
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package main
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import (
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"fmt"
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"sync"
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)
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// channel练习
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var WG sync.WaitGroup
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// 1.启动一个goroutine生成100个数字，发送到ch1
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func set100Num(ch1 chan<- int) { //在声明后添加符号类型表示单向通道
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defer WG.Done()
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for i := 0; i < 100; i++ {
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ch1 <- i
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}
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close(ch1)
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}
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// 2.启动一个goroutine从ch1中取值，计算其平方，放到ch2中
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func get100Num(ch1 <-chan int, ch2 chan<- int) {
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defer WG.Done()
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for {
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x, ok := <-ch1
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if !ok {
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break
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}
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ch2 <- x * x
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}
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close(ch2)
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}
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//3.在main函数中从ch2中取值，打印出来
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func main() {
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e := make(chan int, 50)
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f := make(chan int, 100)
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WG.Add(2)
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go set100Num(e)
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go get100Num(e, f)
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WG.Wait()
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for ret := range f {
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fmt.Printf("通道中数字的平方是：%v\n", ret)
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}
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ch3 := make(chan int, 2)
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ch3 <- 10
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ch3 <- 20
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<-ch3
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<-ch3
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close(ch3) //取完值后关闭通道
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t, ok := <-ch3
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//第三次仍能取到
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fmt.Println("第三此取出的值为", ok, t)
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}
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