enhancement

Author: Alexandre887

1-js/05-data-types/12-json/article.md

@@ -445,7 +445,8 @@ let json = `{
   "surname": *!*'Smith'*/!*,                // mistake: single quotes in value (must be double)
   *!*'isAdmin'*/!*: false,                  // mistake: single quotes in key (must be double)
   "birthday": *!*new Date(2000, 2, 3)*/!*,  // mistake: no "new" is allowed, only bare values
-  "friends": [0,1,2,3]               // here all fine
+  "gender": "male"*!* */!*                  // mistake: missing comma after non-last property
+  "friends": [0,1,2,3]*!*,*/!*              // mistake: there should not be a comma after the last property
 }`;
 ```