Print odd and even numbers alternately with two goroutines.

main.go

package main

func main() {
	odd := make(chan int)
	even := make(chan int)

	// sub-routine print even number
	go func() {
		for i := <-even; i <= 10; i = <-even {
			println("sub : ", i)
			odd <- i + 1
		}
	}()

	// start
	go func() { odd <- 1 }()

	// main-routine print odd number
	for i := <-odd; i <= 10; i = <-odd {
		println("main: ", i)
		even <- i + 1
	}
}