Why can't control leave a finally statement?

Question

When I place a return inside the block of a finally statement, the compiler tells me:

Control cannot leave the body of a finally clause

Example:

try { } catch { } finally {     return; } 

Why is this?

Answer 1

Consider what would happen if you were to return 1 inside the try block and return 0 inside the finally block... Your function would be trying to return two values! The combined options of try and catch are exhaustive in terms of control flow.

Answer 2

It's by design and it's described in C# specification:

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.

It is a compile-time error for a return statement to occur in a finally block.

Also, from C# 6.0 spec draft on MSDN:

It is a compile-time error for a return statement to occur in a finally block.