How to remove these red lines?

[bhuppidhamii]

[fbricon]

see the Problems view in VS Code.

• The revArrayfun method expects you return an int, but nothing is returned. Either return an int or change the return type to void.
• numbers[]= (....) is not valid Java syntax. You probably want to declare

int[] numbers = {2, 4, 6, 8, 10};