A finally block is normally used to perform cleanup operations at the end of a try statement; it is run no matter which way the associated try statement terminates: successful termination, a return statement, or an exception being thrown.

If a finally block contains a return statement or a break or continue statement referring to a loop outside the try statement, this statement will jump out of the finally block, thus overriding any return value or exception throw arising from the try statement. This is often unintentional, and in any case makes the code hard to read.

Carefully inspect all possible control flow paths through the try statement and its finally block. If the jump out of the finally block is unintentional, then correct it. If it is intentional, restructure the code to move the jump into the main try block instead.

The following code snippet contains a try statement that acquires a resource and then performs an action on it. However, if the condition checked by function someCond holds, an Error is thrown instead of performing the action. The finally block releases the resource, and returns true if someOtherCond returns true.

Note that if someCond and someOtherCond both return true, the exception thrown on line 5 is suppressed by the return statement on line 10.

If the suppression of the thrown exception is intentional, the check for someOtherCond should be moved into the try statement like this:

While this transformation leads to some code duplication, it makes the control flow more explicit and easier to understand.

Mozilla Developer Network: try...catch.