| Description |
The Finally keyword is used to mark the start of the final block of statements in a Try statement. They are executed regardless of what happens in the Try statements.
However, the Finally clause does not actually handle any exceptions - the program will terminate if no Except clause is found (see notes below).
Try-Finally is normally used by a routine to allow cleanup processing to take place, such as freeing resources, with the exception being correctly passed to the caller to handle.
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| Notes |
There are times when you want a construct like this :
Try
...
Except
...
Finally
...
End;
where exceptions are trapped and acted upon, but in all cases, a set of clean up statements are executed. This can be achieved with nested Try statements :
Try
Try
...
Except
...
End;
Finally
...
End;
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| Related commands |
| Except |
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Starts the error trapping clause of a Try statement |
| On |
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Defines exception handling in a Try Except clause |
| Raise |
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Raise an exception |
| Try |
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Starts code that has error trapping |
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| Example code : Zero divide with a finally clause |
var
number, zero : Integer;
begin
// Try to divide an integer by zero - to raise an exception
number := -1;
Try
zero := 0;
number := 1 div zero;
ShowMessage('number / zero = '+IntToStr(number));
Finally
if number = -1 then
begin
ShowMessage('Number was not assigned a value - using default');
number := 0;
end;
end;
end;
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| Show full unit code |
Number was not assigned a value - using default
Then, the program terminates with an EDivByZero error message - the finally clause did not trap the error.
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