go_concurrency.say_hello_7.main.go

package main

import (
	"fmt"
	"sync"
)

func main() {
	wg := sync.WaitGroup{}
	wg.Add(1)

	greet := "Hello world!"

	go func(s string) {
		fmt.Println(s)

		wg.Done()
	}(greet)

	greet = "こんにちは世界!"
	wg.Wait()
}