Delphi – E2015 Operator not applicable to this operand type

Posted by AbundantCode

When an operator cannot be applied to the operands it was given, such as when a boolean operator is applied to a pointer, this error message is displayed.

program Produce;
var
  P: ^Integer;
begin
  if P and P^ > 0 then
    Writeln('P points to a number greater 0');
end.

In this case, a C++ programmer was unsure about operator precedence in Delphi because P is not a boolean expression and the comparison must be parenthesized.

program Solve;
var
  P: ^Integer;
begin
  if (P <> nil) and (P^ > 0) then
    Writeln('P points to a number greater 0');
end.

The compiler is pleased if we explicitly compare P to nil and use parentheses.

Tags: