Single::TryParse Method (String, Single%)
Converts the string representation of a number to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- s
- Type: System::String
A string representing a number to convert.
- result
- Type: System::Single%
When this method returns, contains single-precision floating-point number equivalent to the numeric value or symbol contained in s, if the conversion succeeded, or zero if the conversion failed. The conversion fails if the s parameter is nullptr, is not a number in a valid format, or represents a number less than MinValue or greater than MaxValue. This parameter is passed uninitialized.
This overload differs from the Single::Parse(String) method by returning a Boolean value that indicates whether the parse operation succeeded instead of returning the parsed numeric value. It eliminates the need to use exception handling to test for a FormatException in the event that s is invalid and cannot be successfully parsed.
The s parameter can contain PositiveInfinitySymbol, NegativeInfinitySymbol, NaNSymbol (the string comparison is case-sensitive), or a string of the form:
[ws][sign][integral-digits,]integral-digits[.[fractional-digits]][e[sign]exponential-digits][ws]
Elements in square brackets are optional. The following table describes each element.
Element | Description |
|---|---|
ws | A series of white-space characters. |
sign | A negative sign or positive sign symbol. |
integral-digits | A series of numeric characters ranging from 0 to 9 that specify the integral part of the number. Integral-digits can be absent if there are fractional-digits. |
, | A culture-specific group separator symbol. |
. | A culture-specific decimal point symbol. |
fractional-digits | A series of numeric characters ranging from 0 to 9 that specify the fractional part of the number. |
E | An uppercase or lowercase character 'e', that indicates exponential (scientific) notation. |
exponential-digits | A series of numeric characters ranging from 0 to 9 that specify an exponent. |
The s parameter is interpreted using a combination of the NumberStyles::Float and NumberStyles::AllowThousands flags. This means that white space and thousands separators are allowed but currency symbols are not. To explicitly define the elements (such as currency symbols, thousands separators, and white space) that can be present in s, use the TryParse(String, NumberStyles, IFormatProvider, Single%) method overload.
The s parameter is parsed using the formatting information in a NumberFormatInfo object that is initialized for the current system culture. For more information, see NumberFormatInfo::CurrentInfo. To parse a string using the formatting information of some other specified culture, use the TryParse(String, NumberStyles, IFormatProvider, Single%) method overload.
Ordinarily, if you pass the Single::TryParse method a string that is created by calling the Single::ToString method, the original Single value is returned. However, because of a loss of precision, the values may not be equal.
If a separator is encountered in the s parameter during a parse operation, and the applicable currency or number decimal and group separators are the same, the parse operation assumes that the separator is a decimal separator rather than a group separator. For more information about separators, see CurrencyDecimalSeparator, NumberDecimalSeparator, CurrencyGroupSeparator, and NumberGroupSeparator.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.