Format String Parameter

Format strings passed to the string formatting routines contain two types of objects — literal characters and format specifiers. Literal characters are copied verbatim to the resulting string. Format specifiers get a property value from the specified property and apply formatting to it. Only one specifier can exist in the format string.

Format specifiers use the following form:

            "%"["-"][width]["."prec]type

Table 11-1 Format String Characters

Character	Description
%	Indicates start of a format specifier
["—"]	Left justification indicator (optional) Left justifies the result by adding blanks after the value. The default is to right-justify the result by adding blanks before the value.
[width]	Width specifier (optional) Sets the minimum field width for a conversion. If the resulting string is shorter than the minimum field width, it is padded with blanks to increase the field width.
["." prec]	Precision specifier (optional)
type	Conversion type character Conversion characters may be specified in uppercase or lowercase. For all floating-point formats, the actual characters used as decimal and thousand separators are obtained from the DecimalSeparator and ThousandSeparator global variables or their TFormatSettings equivalent. Valid values for type are listed in the following table.

Table 11-2 Format String Type Values

Type Value	Description
d	Decimal The property value must be an integer. The value is converted to a string of decimal digits. If the format string contains a precision specifier, it indicates that the resulting string must contain at least the specified number of digits; if the value has fewer digits, the resulting string is left-padded with zeros.
u	Unsigned decimal Similar to d but no sign is output.
e	Scientific The property value must be a floating-point value. The value is converted to a string of the form "-d.ddd...E+ddd". The resulting string starts with a minus sign if the number is negative. 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 specifier in the format string; a default precision of 15 is assumed if no precision specifier is present. The "E" exponent character in the resulting string is always followed by a plus or minus sign and at least three digits.
f	Fixed The property value must be a floating-point value. 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. The number of digits after the decimal point is given by the precision specifier in the format string; a default of two decimal digits is assumed if no precision specifier is present.
g	General The property value must be a floating-point value. The value is converted to the shortest possible decimal string using fixed or scientific format. The number of significant digits in the resulting string is given by the precision specifier in the format string; a default precision of 15 is assumed if no precision specifier is present. 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.
n	Number The property value must be a floating-point value. The value is converted to a string of the form "-d,ddd,ddd.ddd...". The "n" format corresponds to the "f" format, except that the resulting string contains thousand separators.
m	Money The property value must be a floating-point value. The value is converted to a string that represents a currency amount. The conversion is controlled by the CurrencyString, CurrencyFormat, NegCurrFormat, ThousandSeparator, DecimalSeparator, and CurrencyDecimals global variables or their equivalent in a TFormatSettings data structure. If the format string contains a precision specifier, it overrides the value given by the CurrencyDecimals global variable or its TFormatSettings equivalent.
s	String The property value must be a character, a string, or a PChar value. The string or character is inserted in place of the format specifier. The precision specifier, if present in the format string, specifies the maximum length of the resulting string. If the property value is a string that is longer than this maximum, the string is truncated.
x	Hexadecimal The property value must be an integer value. The value is converted to a string of hexadecimal digits. If the format string contains a precision specifier, it indicates that the resulting string must contain at least the specified number of digits; if the value has fewer digits, the resulting string is left-padded with zeros.