Programming Forums > Application Development > Delphi

bison · Oct 11th, 2005, 2:16 PM

im very new to this, just started it in computing class and im just wondering if anyone could help me. i am trying to make a BMI calculator. i have the formula for it but i run into problems with the last line of the code when trying to turn it from a real to string for putting it into the third text box after using the calculate button and i am not sure how to do so. everything i have tried doesnt work. thanks

zorin · Oct 11th, 2005, 2:21 PM

What code do you already have, Show some and it will be alot easier for people to help out instead of imagining the code in-front of us

Infinite Recursion · Oct 11th, 2005, 2:53 PM

may need to convert data type... code?

bison · Oct 11th, 2005, 3:21 PM

(Toggle Plain Text)

procedure TForm1.Button1Click(Sender: TObject);

var weight:integer;
var height:integer;
var height2:real;
var bmi:real;

begin
weight := strtoint(edit1.text);
height := strtoint(edit2.text);
height2 := height / 100;
bmi := weight / (height2 * height2);
bmi :=      not sure what to do here to put it into edit3.text  

  end;

sorry about this. i know i probably got it all wrong but keep in mind i am very very very new to this and rushed this so could you point out what im doing wrong. thanks alot.

Infinite Recursion · Oct 11th, 2005, 3:25 PM

I don't know Delphi but how about:

edit3.text = inttostr(bmi);

where the inttostr function would be one in which it converts the numeric type of bmi into a string and assigned to the text property of the edit3 textbox.

bison · Oct 11th, 2005, 4:06 PM

thanks for the help. but i get an error when compiling saying "there is no overloaded version of 'IntToStr' that can be called with these arguments". any idea what else i could try?

Infinite Recursion · Oct 11th, 2005, 4:31 PM

Check for a function that can convert 'real' datatypes to strings. The inttostr function is expecting an int and the bmi variable is a real... so it blows up. Get the 'real' equivalent of this converting function and replace the function name in the code above. I don't know what this function name would be as I do not use Delphi.

bison · Oct 11th, 2005, 5:02 PM

its working now. i looked it up and it was floattostr function. thanks alot for all the help. now all i need is to get it to round to 1 decimal place. how can i get it to do that? thanks again for the help

Infinite Recursion · Oct 12th, 2005, 8:17 AM

glad it worked out for you...

For your rounding problem, just looking at google briefly, gave me this:
http://www.latiumsoftware.com/en/delphi/00033.php

(Toggle Plain Text)

function RoundD(x: Extended; d: Integer): Extended;
// RoundD(123.456, 0) = 123.00
// RoundD(123.456, 2) = 123.46
// RoundD(123456, -3) = 123000
var
  n: Extended;
begin
  n := IntPower(10, d);
  x := x * n;
  Result := (Int(x) + Int(Frac(x) * 2)) / n;
end;

bison · Oct 12th, 2005, 2:26 PM

thanks i got that sorted now too. i have one last little problem though. i can get it to show a message when the value of bmi is above or below a certain value, but im not sure how to set it inbetween two values like if >18.5<30 on delphi. how do i do this?

Oct 11th, 2005, 2:16 PM	#1
bison Newbie Join Date: Oct 2005 Posts: 8 Rep Power: 0	need some help please im very new to this, just started it in computing class and im just wondering if anyone could help me. i am trying to make a BMI calculator. i have the formula for it but i run into problems with the last line of the code when trying to turn it from a real to string for putting it into the third text box after using the calculate button and i am not sure how to do so. everything i have tried doesnt work. thanks

Oct 11th, 2005, 2:53 PM	#3
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,467 Rep Power: 8	may need to convert data type... code? __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Oct 11th, 2005, 3:21 PM	#4
bison Newbie Join Date: Oct 2005 Posts: 8 Rep Power: 0	(Toggle Plain Text) procedure TForm1.Button1Click(Sender: TObject); var weight:integer; var height:integer; var height2:real; var bmi:real; begin weight := strtoint(edit1.text); height := strtoint(edit2.text); height2 := height / 100; bmi := weight / (height2 * height2); bmi := not sure what to do here to put it into edit3.text end; procedure TForm1.Button1Click(Sender: TObject); var weight:integer; var height:integer; var height2:real; var bmi:real; begin weight := strtoint(edit1.text); height := strtoint(edit2.text); height2 := height / 100; bmi := weight / (height2 * height2); bmi := not sure what to do here to put it into edit3.text end; sorry about this. i know i probably got it all wrong but keep in mind i am very very very new to this and rushed this so could you point out what im doing wrong. thanks alot.

Oct 11th, 2005, 3:25 PM	#5
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,467 Rep Power: 8	I don't know Delphi but how about: edit3.text = inttostr(bmi); where the inttostr function would be one in which it converts the numeric type of bmi into a string and assigned to the text property of the edit3 textbox. __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Oct 11th, 2005, 4:31 PM	#7
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,467 Rep Power: 8	Check for a function that can convert 'real' datatypes to strings. The inttostr function is expecting an int and the bmi variable is a real... so it blows up. Get the 'real' equivalent of this converting function and replace the function name in the code above. I don't know what this function name would be as I do not use Delphi. __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Oct 11th, 2005, 2:21 PM	#2
zorin Hobbyist Programmer Join Date: Apr 2005 Posts: 218 Rep Power: 4	What code do you already have, Show some and it will be alot easier for people to help out instead of imagining the code in-front of us

Oct 11th, 2005, 4:06 PM	#6
bison Newbie Join Date: Oct 2005 Posts: 8 Rep Power: 0	thanks for the help. but i get an error when compiling saying "there is no overloaded version of 'IntToStr' that can be called with these arguments". any idea what else i could try?

Oct 11th, 2005, 5:02 PM	#8
bison Newbie Join Date: Oct 2005 Posts: 8 Rep Power: 0	its working now. i looked it up and it was floattostr function. thanks alot for all the help. now all i need is to get it to round to 1 decimal place. how can i get it to do that? thanks again for the help

Oct 12th, 2005, 8:17 AM	#9
Infinite Recursion Programming Guru Join Date: Jul 2004 Location: United States Posts: 3,467 Rep Power: 8	glad it worked out for you... For your rounding problem, just looking at google briefly, gave me this: http://www.latiumsoftware.com/en/delphi/00033.php (Toggle Plain Text) function RoundD(x: Extended; d: Integer): Extended; // RoundD(123.456, 0) = 123.00 // RoundD(123.456, 2) = 123.46 // RoundD(123456, -3) = 123000 var n: Extended; begin n := IntPower(10, d); x := x * n; Result := (Int(x) + Int(Frac(x) * 2)) / n; end; function RoundD(x: Extended; d: Integer): Extended; // RoundD(123.456, 0) = 123.00 // RoundD(123.456, 2) = 123.46 // RoundD(123456, -3) = 123000 var n: Extended; begin n := IntPower(10, d); x := x * n; Result := (Int(x) + Int(Frac(x) * 2)) / n; end; __________________ http://jasonpowers.net "There are a thousand hacking at the branches of evil to one who is striking at the root."

Oct 12th, 2005, 2:26 PM	#10
bison Newbie Join Date: Oct 2005 Posts: 8 Rep Power: 0	thanks i got that sorted now too. i have one last little problem though. i can get it to show a message when the value of bmi is above or below a certain value, but im not sure how to set it inbetween two values like if >18.5<30 on delphi. how do i do this?

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Programming Forums > Application Development > Delphi

need some help please