Try-catch-finally-return clarification

Question

By reading all the questions already asked in this forum related to the topic above  see title   I thoroughly understand that finally gets always called   except from System exit and infinite loops    However  I would like to know if a return is called in a catch block and then another return is called from the finally block   For example   public static void main String  args        int a   new TestClass   absorbeTheValue       int absorbeTheValue         try           int a   10 0          if  a  gt  0  return 4        catch Exception e            return 45        finally           return 34                So here the output  when the method is called  is going to be 34 in any case  It means that finally always gets run  I think though that the other  returns  are not run at all  In many posts I found the fact that finally write the content over what had been already written by the catch clause return  My understanding is that as soon as the return value in the catch clause is about to be evaluated  the control flow pass to the finally clause which having in turn another return  this time the return will be evaluated without passing control back to the catch clause  In this way the only return called at runtime will be the finally return  Do you agree with that   A return in finally does not pass back the control to the program but returns the value and terminates the method  Can we say so

User · Answer

Here is some code that show how it works.

class Test
{
    public static void main(String args[]) 
    { 
        System.out.println(Test.test()); 
    }

    public static String test()
    {
        try {
            System.out.println("try");
            throw new Exception();
        } catch(Exception e) {
            System.out.println("catch");
            return "return"; 
        } finally {  
            System.out.println("finally");
            return "return in finally"; 
        }
    }
}

The results is:

try
catch
finally
return in finally

User · Answer

If the return in the try block is reached  it transfers control to the finally block  and the function eventually returns normally  not a throw    If an exception occurs  but then the code reaches a return from the catch block  control is transferred to the finally block and the function eventually returns normally  not a throw    In your example  you have a return in the finally  and so regardless of what happens  the function will return 34  because finally has the final  if you will  word   Although not covered in your example  this would be true even if you didn t have the catch and if an exception were thrown in the try block and not caught  By doing a return from the finally block  you suppress the exception entirely  Consider   public class FinallyReturn     public static final void main String   args        System out println foo args           private static int foo String   args        try         int n   Integer parseInt args 0          return n            finally         return 42                If you run that without supplying any arguments     java FinallyReturn     the code in foo throws an ArrayIndexOutOfBoundsException  But because the finally block does a return  that exception gets suppressed   This is one reason why it s best to avoid using return in finally

[java] Try-catch-finally-return clarification

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