Delphi Compiler Error
W1035 Return value of function ‘%s’ might be undefined
Reason for the Error & Solution
This warning is displayed if the return value of a function has not been assigned a value on every code path.
To put it another way, the function could execute so that it never assigns anything to the return value.
program Produce;
(*$WARNINGS ON*)
var
B: Boolean;
C: (Red,Green,Blue);
function Simple: Integer;
begin
end; (*<-- Warning here*)
function IfStatement: Integer;
begin
if B then
Result := 42;
end; (*<-- Warning here*)
function CaseStatement: Integer;
begin
case C of
Red..Blue: Result := 42;
end;
end; (*<-- Warning here*)
function TryStatement: Integer;
begin
try
Result := 42;
except
Writeln('Should not get here!');
end;
end; (*<-- Warning here*)
begin
B := False;
end.
The problem with procedure IfStatement and CaseStatement is that the result is not assigned in every code path. In TryStatement, the compiler assumes that an exception could happen before Result is assigned.
program Solve;
(*$WARNINGS ON*)
var
B: Boolean;
C: (Red,Green,Blue);
function Simple: Integer;
begin
Result := 42;
end;
function IfStatement: Integer;
begin
if B then
Result := 42
else
Result := 0;
end;
function CaseStatement: Integer;
begin
case C of
Red..Blue: Result := 42;
else Result := 0;
end;
end;
function TryStatement: Integer;
begin
Result := 0;
try
Result := 42;
except
Writeln('Should not get here!');
end;
end;
begin
B := False;
end.
The solution is to make sure there is an assignment to the result variable in every possible code path.
