Can anyone help me fix this code in java or any other language (postfix expression evaluation)?

Question

https://code.sololearn.com/c0M5R924w8ro/?ref=app

Answer 1

There have is not one mistake, but I'll tell you where to start:
The class "Evaluation" and the method of calculation have incorrectly placed "}".
I did not understand the logic, but I ask you to note that the method must return int.
Also, be careful with the implementation of Stack, it does not provide protection against ArrayIndexOutOfBoundsException.