hello world for concurrency

concurrency/hello/go.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+func say(s string) {
+	for i := 0; i < 5; i++ {
+		time.Sleep(time.Millisecond * 100)
+		fmt.Print(s)
+	}
+}
+
+func main() {
+	go say("world!!\n")
+	say("hello ")
+}