contents: fix bug in language constructs for iteration

Author: yangshun

questions/what-language-constructs-do-you-use-for-iterating-over-object-properties-and-array-items/en-US.mdx

@@ -18,8 +18,8 @@ const obj = {
 };
 
 for (const key in obj) {
-  // Optional: to avoid iterating over inherited properties
-  if (obj.hasOwn(obj, key)) {
+  // To avoid iterating over inherited properties
+  if (Object.hasOwn(obj, key)) {
     console.log(`${key}: ${obj[key]}`);
   }
 }