Why C# not allowed to return value from finally block

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Why When you try to return value from Finally block you will get error "Control cannot leave the body of a finally clause

C#

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine( f1());
Console.ReadKey();
}


static int f1()
{
try
{
return 10;
}
finally
{
return 5; // This is where Error occurs
}
}
}
}

Posted 14-Sep-14 19:52pm

vishal_h

Updated 30-Jan-19 19:50pm

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BillWoodruff 15-Sep-14 4:10am

There are a lot of "why" questions about how things work in .NET that can only be answered with the statement: because the language was designed that way.

I'd like to suggest you focus on understanding the try/catch/finally structure as a "whole," rather than focusing on the "pieces"of it. There's little point in using try/finally without a "catch." Understanding how to throw your own Exception (in the "catch"), and understanding of what Exceptions are is very important. cheers, Bill

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Hemant Singh Rautela · Answer 1 · 2014-09-14T20:42:00

You have to write code as :

Just simple code for returns value with finally block... As finally used for cleanup resources...
if any error occurs then catch will execute and set the return value...

SQL

public  bool func_a()
   {
     bool bFlag = true;
     try
        {
          SqlConnection con = new SqlConnection(WebConfigurationManager.ConnectionStrings["Connection"].ConnectionString);
          con.Open();
         // do whatever...
           bFlag = true;
        }
        catch (Exception ex)
        {
            bFlag = false;
        }
        finally
        {
            con.Close();
        }
        return bFlag;

"As finally used for cleanup resources so that the control cant be exit without its completion (cleanup all resources)... "

And as the finally block will always executes whatever condition error occurs or not So we cant place two return statement in a flow... as you used in try block and then in finally block.(if no error occurred then your try code will execute then finally..so how can two return statement will works... )

--------------
It is a compile-time error for a break, continue, or goto statement to transfer control out of a finally block. When a break, continue, or goto statement occurs in a finally block, the target of the statement must be within the same finally block, or otherwise a compile-time error occurs.
From :
http://msdn.microsoft.com/en-us/library/aa664733%28v=vs.71%29.aspx[^]
:-)

*Suvabrata Roy* · Answer 2 · 2014-09-14T20:06:00

Hi,

Read about Finally : http://msdn.microsoft.com/en-IN/library/zwc8s4fz.aspx[^]

Now finally block is used to cleanup your resources which used or initialized in try block, finally is a must run block whatever code is there is should execute every time try has been executed ( If exception occurs then also) so if you return from finally block it will break the execution flow and application may misbehave.

If I did not write any Catch block and Exception occur ?

Still finally block will be executed but it have some dependency on your Machine's CLR settings. For more info : http://msdn.microsoft.com/en-us/magazine/cc793966.aspx[^]

Thanks,
Suvabrata

Pravuprasad · Answer 3 · 2014-09-14T20:38:00

Solution 4

error is that your function is returning two values in try and in final block.for further se
See this for your reference[^]

Posted 14-Sep-14 20:38pm

Pravuprasad

Gihan Liyanage · Answer 4 · 2014-09-14T20:07:00

I think here you may be trying to use the finally block in an odd way. The Framework documentation typifies finally as follows:

The finally block is useful for cleaning up any resources allocated in the try block.

If this were valid code, what would the expected result be? The finally block gets executed after the first return. Does that mean the method should always return 5?

Why C# not allowed to return value from finally block

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