closeChRead.go

package main

import (
	"fmt"
	"sync"
)

func main() {
	ch := make(chan int)
	var wg sync.WaitGroup

	go func() {
		wg.Add(1)
		defer wg.Done()
		for {
			v, ok := <-ch
			if !ok {
				fmt.Println("channel is closed!")
				break
			}
			fmt.Println(v)
		}
	}()

	for i := 0; i < 5; i++ {
		ch <- i
	}
	close(ch)
	wg.Wait()
}

closeChReadRange.go

package main

import (
	"fmt"
	"sync"
)

func main() {
	ch := make(chan int)
	var wg sync.WaitGroup

	go func() {
		wg.Add(1)
		defer wg.Done()
		for v := range ch {
			fmt.Println(v)
		}
	}()

	for i := 0; i < 5; i++ {
		ch <- i
	}
	close(ch)
	wg.Wait()
}

rangeでchannelをreadしている場合、closeで列挙が終了する