Single.TryParse Method

Definition

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.

Overloads

TryParse(ReadOnlySpan<Char>, NumberStyles, IFormatProvider, Single)

Converts the span representation of a number in a specified style and culture-specific format to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.

TryParse(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.

TryParse(ReadOnlySpan<Char>, Single)

Converts the string representation of a number in a character span to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.

TryParse(String, NumberStyles, IFormatProvider, Single)

Converts the string representation of a number in a specified style and culture-specific format to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.

TryParse(ReadOnlySpan<Char>, NumberStyles, IFormatProvider, Single)

Converts the span representation of a number in a specified style and culture-specific format to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.

public:
 static bool TryParse(ReadOnlySpan<char> s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] float % result);
public static bool TryParse (ReadOnlySpan<char> s, System.Globalization.NumberStyles style, IFormatProvider provider, out float result);
static member TryParse : ReadOnlySpan<char> * System.Globalization.NumberStyles * IFormatProvider * single -> bool
Public Shared Function TryParse (s As ReadOnlySpan(Of Char), style As NumberStyles, provider As IFormatProvider, ByRef result As Single) As Boolean

Parameters

s
ReadOnlySpan<Char>

A read-only character span that contains the number to convert. The span is interpreted using the style specified by style

style
NumberStyles

A bitwise combination of enumeration values that indicates the permitted format of s. A typical value to specify is Float combined with AllowThousands.

provider
IFormatProvider

An object that supplies culture-specific formatting information about s.

result
Single

When this method returns, contains the 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 null or Empty, is not in a format compliant with style, represents a number less than MinValue or greater than MaxValue, or if style is not a valid combination of NumberStyles enumerated constants. This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

Returns

true if s was converted successfully; otherwise, false.

TryParse(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.

public:
 static bool TryParse(System::String ^ s, [Runtime::InteropServices::Out] float % result);
public static bool TryParse (string s, out float result);
static member TryParse : string * single -> bool
Public Shared Function TryParse (s As String, ByRef result As Single) As Boolean

Parameters

s
String

A string representing a number to convert.

result
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 null or Empty or is not a number in a valid format. It also fails on .NET Framework and .NET Core 2.2 and earlier versions if s represents a number less than MinValue or greater than MaxValue. This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

Returns

true if s was converted successfully; otherwise, false.

Examples

The following example uses the TryParse(String, Single) method to convert the string representations of numeric values to Single values. It assumes that en-US is the current culture.

string value;
float number;

// Parse a floating-point value with a thousands separator.
value = "1,643.57";
if (Single.TryParse(value, out number))
   Console.WriteLine(number);
else
   Console.WriteLine("Unable to parse '{0}'.", value);      

// Parse a floating-point value with a currency symbol and a 
// thousands separator.
value = "$1,643.57";
if (Single.TryParse(value, out number))
   Console.WriteLine(number);
else
   Console.WriteLine("Unable to parse '{0}'.", value);   

// Parse value in exponential notation.
value = "-1.643e6";
if (Single.TryParse(value, out number))
   Console.WriteLine(number);
else
   Console.WriteLine("Unable to parse '{0}'.", value);   

// Parse a negative integer value.
value = "-168934617882109132";
if (Single.TryParse(value, out number))
   Console.WriteLine(number);
else
   Console.WriteLine("Unable to parse '{0}'.", value);   
// The example displays the following output:
//       1643.57
//       Unable to parse '$1,643.57'.
//       -164300
//       -1.68934617882109E+17
Dim value As String
Dim number As Single

' Parse a floating-point value with a thousands separator.
value = "1,643.57"
If Single.TryParse(value, number) Then
   Console.WriteLine(number)
Else
   Console.WriteLine("Unable to parse '{0}'.", value)      
End If   

' Parse a floating-point value with a currency symbol and a 
' thousands separator.
value = "$1,643.57"
If Single.TryParse(value, number) Then
   Console.WriteLine(number)  
Else
   Console.WriteLine("Unable to parse '{0}'.", value)   
End If

' Parse value in exponential notation.
value = "-1.643e6"
If Single.TryParse(value, number)
   Console.WriteLine(number)
Else
   Console.WriteLine("Unable to parse '{0}'.", value)   
End If

' Parse a negative integer number.
value = "-168934617882109132"
If Single.TryParse(value, number)
   Console.WriteLine(number)
Else
   Console.WriteLine("Unable to parse '{0}'.", value)   
End If
' The example displays the following output:
'       1643.57
'       Unable to parse '$1,643.57'.
'       -1643000
'       -1.68934617882109E+17

Remarks

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 s is out of range of the Single data type, the method returns false on .NET Framework and .NET Core 2.2 and earlier versions. On .NET Core 3.0 and later versions, it returns Single.NegativeInfinity if s is less than Single.MinValue and Single.PositiveInfinity if s is greater than Single.MaxValue.

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.

See also

TryParse(ReadOnlySpan<Char>, Single)

Converts the string representation of a number in a character span to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.

public:
 static bool TryParse(ReadOnlySpan<char> s, [Runtime::InteropServices::Out] float % result);
public static bool TryParse (ReadOnlySpan<char> s, out float result);
static member TryParse : ReadOnlySpan<char> * single -> bool
Public Shared Function TryParse (s As ReadOnlySpan(Of Char), ByRef result As Single) As Boolean

Parameters

s
ReadOnlySpan<Char>

>A character span that contains the string representation of the number to convert.

result
Single

>When this method returns, contains the single-precision floating-point number equivalent of the s parameter, if the conversion succeeded, or zero if the conversion failed. The conversion fails if the s parameter is null or empty or is not a number in a valid format. If is a valid number less than MinValue, result is NegativeInfinity. If is a valid number greater than MaxValue, result is PositiveInfinity. This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

Returns

true if s was converted successfully; otherwise, false.

TryParse(String, NumberStyles, IFormatProvider, Single)

Converts the string representation of a number in a specified style and culture-specific format to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.

public:
 static bool TryParse(System::String ^ s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] float % result);
public static bool TryParse (string s, System.Globalization.NumberStyles style, IFormatProvider provider, out float result);
static member TryParse : string * System.Globalization.NumberStyles * IFormatProvider * single -> bool
Public Shared Function TryParse (s As String, style As NumberStyles, provider As IFormatProvider, ByRef result As Single) As Boolean

Parameters

s
String

A string representing a number to convert.

style
NumberStyles

A bitwise combination of enumeration values that indicates the permitted format of s. A typical value to specify is Float combined with AllowThousands.

provider
IFormatProvider

An object that supplies culture-specific formatting information about s.

result
Single

When this method returns, contains the 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 null or Empty, is not in a format compliant with style, or if style is not a valid combination of NumberStyles enumeration constants. It also fails on .NET Framework or .NET Core 2.2 and earlier versions if s represents a number less than MinValue or greater than MaxValue. This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

Returns

true if s was converted successfully; otherwise, false.

Exceptions

style is not a NumberStyles value.

-or-

style is the AllowHexSpecifier value.

Examples

The following example demonstrates the use of the Single.TryParse(String, NumberStyles, IFormatProvider, Single) method to parse the string representation of numbers that have a particular style and are formatted using the conventions of a particular culture.

string value;
System.Globalization.NumberStyles style;
System.Globalization.CultureInfo culture;
float number;

// Parse currency value using en-GB culture.
value = "£1,097.63";
style = System.Globalization.NumberStyles.Number | 
        System.Globalization.NumberStyles.AllowCurrencySymbol;
culture = System.Globalization.CultureInfo.CreateSpecificCulture("en-GB");
if (Single.TryParse(value, style, culture, out number))
   Console.WriteLine("Converted '{0}' to {1}.", value, number);
else
   Console.WriteLine("Unable to convert '{0}'.", value);

value = "1345,978";
style = System.Globalization.NumberStyles.AllowDecimalPoint;
culture = System.Globalization.CultureInfo.CreateSpecificCulture("fr-FR");
if (Single.TryParse(value, style, culture, out number))
   Console.WriteLine("Converted '{0}' to {1}.", value, number);
else
   Console.WriteLine("Unable to convert '{0}'.", value);

value = "1.345,978";
style = System.Globalization.NumberStyles.AllowDecimalPoint | 
        System.Globalization.NumberStyles.AllowThousands;
culture = System.Globalization.CultureInfo.CreateSpecificCulture("es-ES");
if (Single.TryParse(value, style, culture, out number))
   Console.WriteLine("Converted '{0}' to {1}.", value, number);
else
   Console.WriteLine("Unable to convert '{0}'.", value);

value = "1 345,978";
if (Single.TryParse(value, style, culture, out number))
   Console.WriteLine("Converted '{0}' to {1}.", value, number);
else
   Console.WriteLine("Unable to convert '{0}'.", value);
// The example displays the following output:
//       Converted '£1,097.63' to 1097.63.
//       Converted '1345,978' to 1345.978.
//       Converted '1.345,978' to 1345.978.
//       Unable to convert '1 345,978'.
Dim value As String
Dim style As System.Globalization.NumberStyles
Dim culture As System.Globalization.CultureInfo
Dim number As Single

' Parse currency value using en-GB culture.
value = "£1,097.63"
style = System.Globalization.NumberStyles.Number Or _
        System.Globalization.NumberStyles.AllowCurrencySymbol
culture = System.Globalization.CultureInfo.CreateSpecificCulture("en-GB")
If Single.TryParse(value, style, culture, number) Then
   Console.WriteLine("Converted '{0}' to {1}.", value, number)
Else
   Console.WriteLine("Unable to convert '{0}'.", value)
End If    

value = "1345,978"
style = System.Globalization.NumberStyles.AllowDecimalPoint
culture = System.Globalization.CultureInfo.CreateSpecificCulture("fr-FR")
If Single.TryParse(value, style, culture, number) Then
   Console.WriteLine("Converted '{0}' to {1}.", value, number)
Else
   Console.WriteLine("Unable to convert '{0}'.", value)
End If    

value = "1.345,978"
style = System.Globalization.NumberStyles.AllowDecimalPoint Or _
        System.Globalization.NumberStyles.AllowThousands
culture = System.Globalization.CultureInfo.CreateSpecificCulture("es-ES")
If Single.TryParse(value, style, culture, number) Then
   Console.WriteLine("Converted '{0}' to {1}.", value, number)
Else
   Console.WriteLine("Unable to convert '{0}'.", value)
End If    

value = "1 345,978"
If Single.TryParse(value, style, culture, number) Then
   Console.WriteLine("Converted '{0}' to {1}.", value, number)
Else
   Console.WriteLine("Unable to convert '{0}'.", value)
End If    
' The example displays the following output:
'       Converted '£1,097.63' to 1097.63.
'       Converted '1345,978' to 1345.978.
'       Converted '1.345,978' to 1345.978.
'       Unable to convert '1 345,978'.

Remarks

This overload differs from the Parse(String, NumberStyles, IFormatProvider) 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 style parameter defines the allowable format of the s parameter for the parse operation to succeed. It must be a combination of bit flags from the NumberStyles enumeration. The following NumberStyles members are not supported:

The s parameter can contain PositiveInfinitySymbol, NegativeInfinitySymbol, NaNSymbol for the culture indicated by provider. In addition, depending on the value of style, the s parameter may include the following elements:

[ws] [$] [sign][integral-digits,]integral-digits[.fractional-digits][e[sign]exponential-digits][ws]

Elements in square brackets ([ and ]) are optional. The following table describes each element.

Element Description
ws Optional white space. White space can appear at the beginning of s if style includes the NumberStyles.AllowLeadingWhite flag. It can appear at the end of s if style includes the NumberStyles.AllowTrailingWhite flag.
$ A culture-specific currency symbol. Its position in the string is defined by the NumberFormatInfo.CurrencyNegativePattern or NumberFormatInfo.CurrencyPositivePattern properties of the NumberFormatInfo object returned by the IFormatProvider.GetFormat method of the provider parameter. The currency symbol can appear in s if style includes the NumberStyles.AllowCurrencySymbol flag.
sign An optional sign. The sign can appear at the beginning of s if style includes the NumberStyles.AllowLeadingSign flag, and it can appear at the end of s if style includes the NumberStyles.AllowTrailingSign flag. Parentheses can be used in s to indicate a negative value if style includes the NumberStyles.AllowParentheses flag.
integral-digits A series of digits 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 thousands separator symbol. The current culture's thousands separator symbol can appear in s if style includes the NumberStyles.AllowThousands flag.
. A culture-specific decimal point symbol. The current culture's decimal point symbol can appear in s if style includes the NumberStyles.AllowDecimalPoint flag.
fractional-digits A series of digits ranging from 0 to 9 that specify the fractional part of the number. Fractional digits can appear in s if style includes the NumberStyles.AllowDecimalPoint flag.
e The e or E character, which indicates that s can represent a number using exponential notation. The s parameter can represent a number in exponential notation if style includes the NumberStyles.AllowExponent flag.
exponential-digits A series of digits ranging from 0 to 9 that specify an exponent.

Note

Any terminating NUL (U+0000) characters in s are ignored by the parsing operation, regardless of the value of the style argument.

A string with digits only (which corresponds to the NumberStyles.None style) always parses successfully if it is in the range of the Single type. The remaining System.Globalization.NumberStyles members control elements that may be but are not required to be present in the input string. The following table indicates how individual NumberStyles flags affect the elements that may be present in s.

NumberStyles value Elements permitted in s in addition to digits
None The integral-digits element only.
AllowDecimalPoint The . and fractional-digits elements.
AllowExponent The s parameter can also use exponential notation. This flag by itself supports values in the form integral-digitsEexponential-digits; additional flags are needed to successfully parse strings in exponential notation with such elements as positive or negative signs and decimal point symbols.
AllowLeadingWhite The ws element at the beginning of s.
AllowTrailingWhite The ws element at the end of s.
AllowLeadingSign The sign element at the beginning of s.
AllowTrailingSign The sign element at the end of s.
AllowParentheses The sign element in the form of parentheses enclosing the numeric value.
AllowThousands The , element.
AllowCurrencySymbol The $ element.
Currency All. The s parameter cannot represent a hexadecimal number or a number in exponential notation.
Float The ws element at the beginning or end of s, sign at the beginning of s, and the . symbol. The s parameter can also use exponential notation.
Number The ws, sign, thousands separator (,), and decimal point (.) elements.
Any All styles, except s cannot represent a hexadecimal number.

The provider parameter is an IFormatProvider implementation whose GetFormat method returns a NumberFormatInfo object that provides culture-specific formatting information. When the TryParse(String, NumberStyles, IFormatProvider, Single) method is invoked, it calls the provider parameter's GetFormat method and passes it a Type object that represents the NumberFormatInfo type. The GetFormat method then returns the NumberFormatInfo object that provides information about the format of the s parameter. There are three ways to use the provider parameter to supply custom formatting information to the parse operation:

  • You can pass a CultureInfo object that represents the culture that supplies formatting information. Its GetFormat method returns the NumberFormatInfo object that provides numeric formatting information for that culture.

  • You can pass the actual NumberFormatInfo object that provides numeric formatting information. (Its implementation of GetFormat just returns itself.)

  • You can pass a custom object that implements IFormatProvider. Its GetFormat method instantiates and returns the NumberFormatInfo object that provides formatting information.

If provider is null, the formatting of s is interpreted based on the NumberFormatInfo object of the current culture.

If s is out of range of the Single data type, the method throws an OverflowException on .NET Framework and .NET Core 2.2 and earlier versions. On .NET Core 3.0 and later versions, it returns Single.NegativeInfinity if s is less than Single.MinValue and Single.PositiveInfinity if s is greater than Single.MaxValue.

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.

See also

Applies to