Writing to a closed channel in Go lang

closed.go

package main

import (
	"fmt"
	"time"
)

func main() {
	chans := []chan int{
		make(chan int, 1),
		make(chan int, 1),
		make(chan int, 1),
		make(chan int, 1),
		make(chan int, 1),
	}

	close(chans[1]) // closing random channel
	close(chans[4]) // closing one more random channel

	closed := []int{}
	for i, ch := range chans {
		go func(i int, ch chan int) {
			defer func() {
				// recoverint from panic caused by writing to a closed channel
				if recover() == nil {
					return
				}
				
				fmt.Println("Channel", i, "is closed. Removing it from the list")
				closed = append(closed, i)
			}()
			ch <- 1 // writing to channel which may be already closed
		}(i, ch)
	}
	time.Sleep(1)

	deleted := 0
	for _, i := range closed {
		chans = append(chans[:i-deleted], chans[i-deleted+1:]...)
		deleted++
	}

	fmt.Println(len(chans), "channels left")
}