System.WideString.FloatToStrF
C++
static WideString FloatToStrF(long double value,
TStringFloatFormat format,
int precision, int digits);
Properties
Type | Visibility | Source | Unit | Parent |
---|---|---|---|---|
function | public | wstring.h | System | WideString |
Description
Returns the string representation of a floating-point value.
The format parameter controls the format of the resulting string. The precision parameter specifies the precision of the given value. It should be 7 or less for values of type float, 15 or less for values of type double, and 18 or less for values of type Extended. The meaning of the digits parameter depends on the particular format selected.
The possible values of the format parameter, and the meaning of each, are described in the following table.
Value | Meaning |
---|---|
sffGeneral |
General number format. The value is converted to the shortest possible decimal string using fixed or scientific format. Trailing zeros are removed from the resulting string, and a decimal point appears only if necessary. The resulting string uses fixed-point format if the number of digits to the left of the decimal point in the value is less than or equal to the specified precision, and if the value is greater than or equal to 0.00001. Otherwise, the resulting string uses scientific format, and the digits parameter specifies the minimum number of digits in the exponent (from 0 through 4). |
sffExponent |
Scientific format. The value is converted to a string of the form "-d.ddd...E+dddd". The resulting string starts with a minus sign if the number is negative, and one digit always precedes the decimal point. The total number of digits in the resulting string (including the one before the decimal point) is given by the precision parameter. The "E" exponent character in the resulting string is always followed by a plus or minus sign and up to four digits. The digits parameter specifies the minimum number of digits in the exponent (from 0 through 4). |
sffFixed |
Fixed-point format. The value is converted to a string of the form "-ddd.ddd...". The resulting string starts with a minus sign if the number is negative, and at least one digit always precedes the decimal point. The number of digits after the decimal point is given by the digits parameter--it must be from 0 through 18. If the number of digits to the left of the decimal point is greater than the specified precision, the resulting value will use scientific format. |
sffNumber |
Number format. The value is converted to a string of the form "-d,ddd,ddd.ddd...". The sffNumber format corresponds to the sffFixed format, except that the resulting string contains thousand separators. |
sffCurrency |
Currency format. The value is converted to a string that represents a currency amount. The conversion is controlled by the CurrencyString, CurrencyFormat, NegCurrFormat, ThousandSeparator, and DecimalSeparator global variables, all of which are initialized from the Currency Format in the International section of the Windows Control Panels. The number of digits after the decimal point is given by the Digits parameter--it must be from 0 through 18. |
For all formats, the actual characters used as decimal and thousand separators are obtained from the DecimalSeparator and ThousandSeparator global variables.
If the given value is a NAN (not-a-number), the resulting string is 'NAN'. If the given value is positive infinity, the resulting string is 'INF'. If the given value is negative infinity, the resulting string is '-INF'.