diff --git a/maps/demo1.go b/maps/demo1.go
index 0834ca1..4b6a659 100644
--- a/maps/demo1.go
+++ b/maps/demo1.go
@@ -11,4 +11,6 @@ func Demo1()  {
 	
 	fmt.Println(my_dictionary["book"])
 	fmt.Println("String number : ", len(my_dictionary))
+	delete(my_dictionary, "book")
+	fmt.Println("String number : ", len(my_dictionary))
 }
\ No newline at end of file