Mega Code Archive
Floattostrf - convert a floating point value to a string with formatting sysutils unit
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1 function FloatToStrF ( Value : Extended; Format : TFloatFormat; Precision, Digits : Integer ) : string;
2 function FloatToStrF ( Value : Extended; Format : TFloatFormat; Precision, Digits : Integer; const FormatSettings : TFormatSettings ) : string;
Description
The FloatToStrF function converts a floating point number Value into a displayable string, with great control over the formatting via the Format, Precision, and Digits values.
The Value type may be any of the floating point types.
The Format parameter is defined by the TFloatFormat (SysUtils) type :
ffCurrency eg : £2,345.60
ffExponent eg : 2.3456E+04
ffFixed eg : 2345.60
ffGeneral eg : 2345.6
ffNumber eg : 2,345.6
The other parameters are dependent on this format. See TFloatFormat for full details.
Version 2 of this function is for use within threads. You furnish the FormatSettings record before invoking the call. It takes a local copy of global formatting variables that make the routine thread safe.
Notes
You can change the currency string from the default (such as '$' in the USA, '£' in the UK) using the CurrencyString variable.
You can change the position of the currency string using the CurrencyFormat variable.
You can change the decimal point value by setting the DecimalSeparator character.
You can change the thousands separator value by setting the ThousandSeparator character.
If the full number of digits before the decimal point (the mantissa) cannot be displayed, then the display reverts to the exponent (scientific) format.
Related commands
CurrencyDecimals Defines decimal digit count in the Format function
CurrencyFormat Defines currency string placement in curr display functions
CurrencyString The currency string used in currency display functions
DecimalSeparator The character used to display the decimal point
FloatToStr Convert a floating point value to a string
NegCurrFormat Defines negative amount formatting in currency displays
TFloatFormat Formats for use in floating point number display functions
ThousandSeparator The character used to display the thousands separator
Example code : Display numbers as financial values
var
amount1 : Extended;
begin
amount1 := 1234.567;
// Display in a Currency format
CurrencyString := '£ ';
ShowMessage('Using 8,4 = '+FloatToStrF(amount1, ffCurrency, 8, 4));
ShowMessage('Using 4,4 = '+FloatToStrF(amount1, ffCurrency, 4, 4));
ShowMessage('Using 4,2 = '+FloatToStrF(amount1, ffCurrency, 4, 2));
ShowMessage('Using 2,4 = '+FloatToStrF(amount1, ffCurrency, 2, 4));
end;
Show full unit code
Using 8,4 = £ 1,234.5670
Using 4,4 = £ 1,235.0000
Using 4,2 = £ 1,235.00
Using 2,4 = 1.2E0003
Example code : Display numbers with Scientific formatting
var
amount1 : Extended;
begin
amount1 := 1234.567;
// Display in a Scientific format
ShowMessage('Using 8,4 = '+FloatToStrF(amount1, ffExponent, 8, 4));
ShowMessage('Using 4,4 = '+FloatToStrF(amount1, ffExponent, 4, 4));
ShowMessage('Using 4,2 = '+FloatToStrF(amount1, ffExponent, 4, 2));
ShowMessage('Using 2,4 = '+FloatToStrF(amount1, ffExponent, 2, 4));
end;
Show full unit code
Using 8,4 = 1.2345670E+0003
Using 4,4 = 1.235E+0003
Using 4,2 = 1.235E+03
Using 2,4 = 1.2E+0003
Example code : General display of numbers
var
amount1 : Extended;
begin
amount1 := 1234.567;
// Display in Fixed format
ShowMessage('Fixed formatting :');
ShowMessage('');
ShowMessage('Using 8,4 = '+FloatToStrF(amount1, ffFixed, 8, 4));
ShowMessage('Using 4,4 = '+FloatToStrF(amount1, ffFixed, 4, 4));
ShowMessage('Using 4,2 = '+FloatToStrF(amount1, ffFixed, 4, 2));
ShowMessage('Using 2,4 = '+FloatToStrF(amount1, ffFixed, 2, 4));
// Display in General format
ShowMessage('');
ShowMessage('General formatting :');
ShowMessage('');
ShowMessage('Using 8,4 = '+FloatToStrF(amount1, ffGeneral, 8, 4));
ShowMessage('Using 4,4 = '+FloatToStrF(amount1, ffgeneral, 4, 4));
ShowMessage('Using 4,2 = '+FloatToStrF(amount1, ffGeneral, 4, 2));
ShowMessage('Using 2,4 = '+FloatToStrF(amount1, ffGeneral, 2, 4));
// Display in Number format
ShowMessage('');
ShowMessage('Number formatting :');
ShowMessage('');
ShowMessage('Using 8,4 = '+FloatToStrF(amount1, ffNumber, 8, 4));
ShowMessage('Using 4,4 = '+FloatToStrF(amount1, ffNumber, 4, 4));
ShowMessage('Using 4,2 = '+FloatToStrF(amount1, ffNumber, 4, 2));
ShowMessage('Using 2,4 = '+FloatToStrF(amount1, ffNumber, 2, 4));
end;
Show full unit code
Fixed formatting :
Using 8,4 = 1234.5670
Using 4,4 = 1235.0000
Using 4,2 = 1235.00
Using 2,4 = 1.2E0003
General formatting :
Using 8,4 = 1234.567
Using 4,4 = 1235
Using 4,2 = 1235
Using 2,4 = 1.2E0003
Number formatting :
Using 8,4 = 1,234.5670
Using 4,4 = 1,235.0000
Using 4,2 = 1,235.00
Using 2,4 = 1.2E0003
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