Delphi: How to correctly divide to a float number

Question

First day using Delphi Community IDE, I've been able to create a calculator app. I've done mostly Python and R programming.

But I'm having trouble with the Division Operation. I've hardcoded 2 values just to make sure the operation is based on float numbers.

I would like to get 2.5 in the panel caption, when dividing 5 to 2.

iAns := 5 / 2.0; yields:

[dcc32 Error] hello_world.pas(189): E2010 Incompatible types: 'Integer' and 'Extended'
[dcc32 Error] hello_world.pas(189): E2010 Incompatible types: 'Integer' and 'Extended'
[dcc32 Fatal Error] Project1.dpr(5): F2063 Could not compile used unit 'hello_world.pas'

This is the function that does the operation based on if else conditionals:

procedure TForm1.btnEqualsClick(Sender: TObject);
begin
iNum2 := StrToInt(edt1.Text);
edt1.Clear;
ShowMessage(IntToStr(iNum1));
ShowMessage(IntToStr(iNum2));

if Operant = '+' then
    begin
        iAns := iNum1 + iNum2;
        pnl1.Caption :=  IntToStr(iAns);
    end
else if Operant = '-' then
    begin
        iAns := iNum1 - iNum2;
        pnl1.Caption :=  IntToStr(iAns);
    end
else if Operant = '*' then
    begin
        iAns := iNum1 * iNum2;
        pnl1.Caption :=  IntToStr(iAns);
    end
else if Operant = '/' then
    begin
        iAns := 5 / 2.0;
        pnl1.Caption :=  FloatToStr(iAns);
    end
end;

end.

UPDATE 1:

var
  Form1: TForm1;
  iNum1, iNum2, iAns : Integer;
  rNum1, rNum2, rAns : Integer;
  Operant : String;

user_282848 · Answer

iAns is declared as an integer. And a variable of integer type cannot hold a non-integral value like 2.5, which is what you get by 5 / 2.0. You need to declare iAns with a floating-point type instead, like double (or real, single, extended: read the documentation about these).

Some additional hints:

5 / 2 will work just as well as 5 / 2.0, since the / operator always performs a floating-point division. You will get 2.5.
Delphi also has an integer division operator, div. 5 div 2 yields the integer 2.

Notice how the compiler actually told you this already. It probably pointed you to the line iAns := 5 / 2.0 telling you that integer (the type of iAns) isn't compatible with extended (the type of the right-hand side).

Delphi: How to correctly divide to a float number

1 Answers