As
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The operator as performs a conditional typecast.
The word as is a reserved word in {$mode Delphi} and {$mode objFPC}.
operation
as requires a class or (COM) interface as the first argument and a class or interface reference as the second.
The expression child as super is equivalent to the expression and statement:
super(child)
if not assigned(child) and_then not child is super then
begin
raise exception.create(sErrInvalidTypecast);
end;
Warning: Typecasting a nil pointer will not raise an exception.
However, trying to de-reference nil by attempting to access an attribute or method will cause a RTE.
application
as ensures a typecast is legit.
as is one of the operators that can not be overloaded.
