channel疑问

代码如下，为啥是轮循打印两遍 package main

import ( "fmt" )

func main() { ch := make(chan int) go func() { for i := 0; i <= 5; i++ { fmt.Println("子go程写",i) ch <- i } }()

for i := 0; i <= 5; i++ {
    j := <-ch
    fmt.Println("主go程读", j)
}

}