Merge pull request #193 from liusongsen/patch-3

{"Name":"Wednesday","Age":6,"Parents":["Gomez","Morticia"]}

ebook/07.2.md

@@ -88,6 +88,8 @@ JSON（Javascript Object Notation）是一种轻量级的数据交换语言，
 			fmt.Println(k, "is string", vv)
 		case int:
 			fmt.Println(k, "is int", vv)
+		case float64:
+			fmt.Println(k,"is float64",vv)
 		case []interface{}:
 			fmt.Println(k, "is an array:")
 			for i, u := range vv {