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FormatRealToString


Header: STD.h
Namespace: avl

Creates a string from a real number using a proper format.

Applications: Useful for preparing a number for display or communication with specific number of fractional digits, sign etc.

Syntax

void avl::FormatRealToString
(
	const float inReal,
	const int inIntegerDigitCount,
	const int inFractionalDigitCount,
	const atl::String& inDecimalMark,
	const atl::String& inTrailingCharacter,
	const bool inForceSignPrinting,
	const atl::String& inSuffix,
	atl::String& outString
)

Parameters

Name Type Range Default Description
Input value inReal const float Input real
Input value inIntegerDigitCount const int 0 - 1000 How many characters the integer part of the input real should have at least
Input value inFractionalDigitCount const int 0 - 100 3 How many characters the fractional part of the input real should have
Input value inDecimalMark const String& \".\" The symbol used to separate the integer part from the fractional part of the number
Input value inTrailingCharacter const String& \"0\" Defines the trailing character
Input value inForceSignPrinting const bool False Forces printing the sign of the number even if the number is positive
Input value inSuffix const String& \"\" Defines a suffix. Generally it is an unit of value (e.g. mm)
Output value outString String& Output string

Examples

inReal = 3.14159265359
inIntegerDigitCount = 2
inFractionalDigitCount = 3
inDecimalMark = "."
inTrailingCharacter = "0"
inForceSignPrinting = False
inSuffix = "..."
outString = "03.142..."

In the example above desired integer digit count defined in inIntegerDigitCount equals 2, so the filter attaches trailing sign (zero) at the beginning of the result outString. Decimal mark (inDecimalMark) is set as a dot and the number of fractional digits (inFractionalDigitCount) as 3. The result string ends with ellipsis defined in inSuffix and the final result is "03.142...".
Note that the third digit was rounded up to "2" due to the succeeding digit.

inReal = 10.7
inIntegerDigitCount = 1
inFractionalDigitCount = 2
inDecimalMark = ","
inTrailingCharacter = " "
inForceSignPrinting = True
inSuffix = " °C"
outString = "+10,70 °C"

This example demonstrates formatting of value 10.7 with one integer digit as defined in inIntegerDigitCount and two fractional digits described by inFractionalDigitCount. Note that the integer part of formatted number (1) is less than digits in integral part of passed value (10), but it doesn't affect to either (unlike the fractional part which can cuts off excessing digits).
Trailing character (inTrailingCharacter) doesn't affect to anything, because desired integer digit count is one (the same effect would be for zero).

Remarks

If you want to cut off excessing digits from a fractional part of a number (instead of rounding them), you can format a number with one extra precision digit and then use Substring to cut off the last digit. You can add a suffix manually by using AvsFilter_ConcatenateStrings.

Errors

List of possible exceptions:

Error type Description
DomainError inDecimalMark has to be a single character in FormatRealToString.
DomainError inTrailingCharacter has to be a single character in FormatRealToString.

See Also

  • FormatString – Creates a string according to the given format and data.