Checking for number or not

[stab]

Hi,

Is there some kind of function like IsANumber to use when reading data from a list containing a range of numbers delimited by a nonNumber?

[paule32]

Try this Code:

Code: Pascal  [Select][+][-]

1. function IsNum(const S: string): Boolean;
2. var
3.   I: Integer;
4. begin
5.   Result := (S <> '');
6.   for I := 1 to Length(S) do
7.   begin
8.     if not (S[I] in ['0'..'9']) then
9.     begin
10.       Result := False;
11.       Exit;
12.     end;
13.   end;
14. end;

HTH - Hope This Helps

[stab]

Thank you, but it doesn't work.

I'm using TAContour for contouring a lot of black areas in an image and get¨the result in a TLineSerie where all polygones are separated with some kind of nonNumber. When trying to use your code I get following error when compiling:
Error: Incompatible type for arg no. 1: Got "Double", expected "AnsiString"

[alpine]

Hi,

Is there some kind of function like IsANumber to use when reading data from a list containing a range of numbers delimited by a nonNumber?

Please give an example of such a list. IsANumber as opposed to nonNumber won't give you a chance to separate the test sub-strings between the delimiters (non-number) at the first place.   

@paule32
The Val() procedure is suitable for that

[Nimbus]

https://www.freepascal.org/docs-html/rtl/math/isnan.html

This?

[jamie]

Thank you, but it doesn't work.

I'm using TAContour for contouring a lot of black areas in an image and get¨the result in a TLineSerie where all polygones are separated with some kind of nonNumber. When trying to use your code I get following error when compiling:
Error: Incompatible type for arg no. 1: Got "Double", expected "AnsiString"

Then you are not parsing a string but a double which is a binary image of a floating point

[stab]

Thanks to your all and especially to Nimbus. Your tip made it

[Bart]

My IsNumeric in my fsisillystuff.pp unit can parse string representing (big)integers, including strings in binary, octal, hexadecimal, roman notation and (big)floating point numbers.
Currently it cannot parse complex numbers though.

Bart

[MarkMLl]

I'm troubled by this thread. IsNaN() takes a real- not a string- as a parameter and looks for the specific NaN bit pattern, which begs the question of what's being used for parsing that returns a NaN if it doesn't like what it sees.

There's a whole lot of TryXXX() functions for conditionally parsing strings, for example https://www.freepascal.org/docs-html/current/rtl/sysutils/trystrtofloat.html and https://www.freepascal.org/docs-html/current/rtl/sysutils/trystrtoint.html .

MarkMLl

[Nimbus]

Guys. The TS never said he needed to parse a string. He's plotting a Chart with TLineSeries, what he's got is an array of floating points. Some of which apparently are Not a Number in the sense of IEEE 754 NaN - therefore he needed a method to check against those values.

[alpine]

Guys. The TS never said he needed to parse a string. He's plotting a Chart with TLineSeries, what he's got is an array of floating points. Some of which apparently are Not a Number in the sense of IEEE 754 NaN - therefore he needed a method to check against those values.

Yeah. But he mentioned TLineSeries latter in his second post and shortly before I posted my request for clarification. The initial post was confusing and rather logically contradictory.

Nevermind, It seems he got his question answered, which is what's important.

[paule32]

what is the meaning of: TS ?

TS = Terminal Server
TS = Topic Starter
TS = Toast Side
?

[wp]

TS = thread starter