exercise: interfaces - stringers

exercises/stringers.go

@@ -0,0 +1,19 @@
+package main
+
+import "fmt"
+
+type IPAddr [4]byte
+
+func (i IPAddr) String() string {
+	return fmt.Sprintf("\"%d.%d.%d.%d\"", i[0], i[1], i[2], i[3])
+}
+
+func main() {
+	hosts := map[string]IPAddr{
+		"loopback":  {127, 0, 0, 1},
+		"googleDNS": {8, 8, 8, 8},
+	}
+	for name, ip := range hosts {
+		fmt.Printf("%v: %v\n", name, ip)
+	}
+}