Waitgroup counter order

#1

I am using waitgroups for the first time. I ran the code but the order in which the code runs is opposite of what I expect.
Expected result:
Hello, playground
Counter: 0
Counter: 1

Kindly help me.
https://play.golang.org/p/U4TDVTbDzN4

#2

Your expectation is wrong. The goroutine scheduler is not deterministic.

package main

import (
	"fmt"
	"sync"
)

var wg sync.WaitGroup

func printer(counter int) {
	fmt.Println("Counter:\t", counter)
	wg.Done()
}

func main() {
	counter := 0
	for i := 0; i < 10; i++ {
		wg.Add(1)
		go printer(counter)
		counter++
	}
	wg.Wait()
}

https://play.golang.org/p/wMs_I-7MRxN.

. Run 1:
Counter: 9
Counter: 0
Counter: 1
Counter: 2
Counter: 3
Counter: 4
Counter: 5
Counter: 7
Counter: 6
Counter: 8
. Run 2:
Counter: 9
Counter: 0
Counter: 1
Counter: 5
Counter: 2
Counter: 3
Counter: 4
Counter: 7
Counter: 6
Counter: 8
. Run 3:
Counter: 9
Counter: 3
Counter: 0
Counter: 1
Counter: 2
Counter: 6
Counter: 4
Counter: 5
Counter: 7
Counter: 8
.

#3

Thanks for the help.
Really appreciate it.