TextToFloat¶

Convert a buffer to a float value.

Declaration¶

Source position: sysstrh.inc line 225

function TextToFloat(Buffer: PChar; out Value: Extended) : Boolean;

function TextToFloat(Buffer: PChar; out Value: Extended; 
                    const FormatSettings: TFormatSettings) : Boolean;

function TextToFloat(Buffer: PChar; out Value; ValueType: TFloatValue)
                     : Boolean;

function TextToFloat(Buffer: PChar; out Value; ValueType: TFloatValue; 
                    const FormatSettings: TFormatSettings) : Boolean;

Description¶

TextToFloat converts the string in Buffer to a floating point value. Buffer should contain a valid string representation of a floating point value (either in decimal or scientific notation).

If the buffer contains a decimal value, then the decimal separator character must be the value of the DecimalSeparator variable.

Remark:

Note that this behaviour has changed, earlier implementations also allowed the use of '.' in addition to the decimal separator character.

The function returns True if the conversion was successful.

Errors¶

If there is an invalid character in the buffer, then the function returns False

Example¶

Program Example91;

{ This program demonstrates the TextToFloat function }
{$mode objfpc}
{$h+ }

Uses SysUtils;

Const
  NrValues = 5;
  TestStr : Array[1..NrValues] of pchar =
           ('1,1','-0,2','1,2E-4','0','1E4');

Procedure Testit;

Var
  I : Integer;
  E : Extended;

begin
  Writeln('Using DecimalSeparator : ',DecimalSeparator);
  For I:=1 to NrValues do
    begin
    Writeln('Converting : ',TestStr[i]);
    If TextToFloat(TestStr[i],E) then
      Writeln('Converted value : ',E)
    else
      Writeln('Unable to convert value.');
    end;
end;

Begin
  DecimalSeparator:=',';
  Testit;
  DecimalSeparator:='.';
  Testit;
End.

Name	Description
StrToFloat	Convert a string to a floating-point value.
FloatToStr	Convert a float value to a string using a fixed format.
FormatFloat	Format a float according to a certain mask.