select-chan_1.go

package main

import (
	"log"
	"time"
)

func main() {
	c1 := make(chan string)
	c2 := make(chan string)

	go func() {
		time.Sleep(time.Second * 1)
		log.Print("data from c1")
		c1 <- "one second"
	}()
	go func() {
		time.Sleep(time.Second * 3)
		log.Print("data from c2")
		c2 <- "three seconds"
	}()

	for i := 0; i < 2; i++ {
		select {
		case x1 := <-c1:
			log.Printf("result from c1: %v", x1)
		case x2 := <-c2:
			log.Printf("result from c2: %v", x2)
		}
	}
}

select-chan_2.go

package main

import (
	"log"
	"time"
)

func main() {
	c1 := make(chan string)
	c2 := make(chan string)

	go func() {
		time.Sleep(time.Second * 1)
		x1 := <-c1
		log.Printf("result from c1: %v", x1)
	}()
	go func() {
		time.Sleep(time.Second * 3)
		x2 := <-c2
		log.Printf("result from c2: %v", x2)

	}()

	for i := 0; i < 2; i++ {
		select {
		case c1 <- "one second":
			log.Printf("sent one")
		case c2 <- "three seconds":
			log.Printf("sent three")
		}
	}
}