Fix arr.length in example & point to Java 25 docs (exercism#3114)

bull1210 · web-flow · commit 7b0f3507f2d5 · 2026-04-27T21:15:09.000+08:00
Co-Authored-By: bull1210 &lt;bull1210@gmail.com&gt;
diff --git a/concepts/nullability/about.md b/concepts/nullability/about.md
@@ -28,7 +28,7 @@ Whilst accessing a reference variable which has a value of `null` will compile f
 int[] arr = null;
 
 // Throws NullPointerException at runtime
-arr.Length;
+arr.length;
 ```
 
 A [`NullPointerException` is thrown][null-pointer-exception] when trying to access a reference variable which is null but requires an object.
diff --git a/docs/RESOURCES.md b/docs/RESOURCES.md
@@ -2,5 +2,5 @@
 
 - [Stack Overflow](http://stackoverflow.com/questions/tagged/java).
 - [The Java subreddit](https://www.reddit.com/r/java)
-- [Official Java documentation](https://docs.oracle.com/en/java/javase/11/docs/api/index.html)
+- [Official Java documentation](https://docs.oracle.com/en/java/javase/25/docs/api/index.html)
 - [Java Programming Books](https://github.com/EbookFoundation/free-programming-books/blob/main/books/free-programming-books-langs.md#java)
