SByte.TryParse Method (System) (original) (raw)

Source:

SByte.cs

Source:

SByte.cs

Source:

SByte.cs

Source:

SByte.cs

Tries to convert the string representation of a number in a specified style and culture-specific format to its SByte equivalent, and returns a value that indicates whether the conversion succeeded.

public:
 static bool TryParse(System::String ^ s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::SByte % result);

public:
 static bool TryParse(System::String ^ s, System::Globalization::NumberStyles style, IFormatProvider ^ provider, [Runtime::InteropServices::Out] System::SByte % result) = System::Numerics::INumberBase<System::SByte>::TryParse;

[System.CLSCompliant(false)]
public static bool TryParse(string s, System.Globalization.NumberStyles style, IFormatProvider provider, out sbyte result);

public static bool TryParse(string? s, System.Globalization.NumberStyles style, IFormatProvider? provider, out sbyte result);

[System.CLSCompliant(false)]
public static bool TryParse(string? s, System.Globalization.NumberStyles style, IFormatProvider? provider, out sbyte result);

[<System.CLSCompliant(false)>]
static member TryParse : string * System.Globalization.NumberStyles * IFormatProvider * sbyte -> bool

static member TryParse : string * System.Globalization.NumberStyles * IFormatProvider * sbyte -> bool

Public Shared Function TryParse (s As String, style As NumberStyles, provider As IFormatProvider, ByRef result As SByte) 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 Integer.

provider

IFormatProvider

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

result

SByte

When this method returns, contains the 8-bit signed integer value equivalent to the number 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 represents a number less than SByte.MinValue or greater than SByte.MaxValue. This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

Returns

true if s was converted successfully; otherwise, false.

Attributes

Exceptions

Examples

The following example calls the TryParse(String, NumberStyles, IFormatProvider, SByte) method with a number of different string and NumberStyles values.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      string numericString;
      NumberStyles styles;
      
      numericString = "106";
      styles = NumberStyles.Integer;
      CallTryParse(numericString, styles);
      
      numericString = "-106";
      styles = NumberStyles.None;
      CallTryParse(numericString, styles);
      
      numericString = "103.00";
      styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
      CallTryParse(numericString, styles);
      
      numericString = "103.72";
      styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
      CallTryParse(numericString, styles);

      numericString = "10E-01";
      styles = NumberStyles.Integer | NumberStyles.AllowExponent;
      CallTryParse(numericString, styles); 
      
      numericString = "12E-01";
      CallTryParse(numericString, styles);
          
      numericString = "12E01";
      CallTryParse(numericString, styles); 
      
      numericString = "C8";
      CallTryParse(numericString, NumberStyles.HexNumber);
      
      numericString = "0x8C";
      CallTryParse(numericString, NumberStyles.HexNumber);
   }
   
   private static void CallTryParse(string stringToConvert, NumberStyles styles)
   {
      sbyte number;
      bool result = SByte.TryParse(stringToConvert, styles, 
                                   CultureInfo.InvariantCulture, out number);
      if (result)
         Console.WriteLine($"Converted '{stringToConvert}' to {number}.");
      else
         Console.WriteLine($"Attempted conversion of '{stringToConvert}' failed.");
   }
}
// The example displays the following output:
//       Converted '106' to 106.
//       Attempted conversion of '-106' failed.
//       Converted '103.00' to 103.
//       Attempted conversion of '103.72' failed.
//       Converted '10E-01' to 1.
//       Attempted conversion of '12E-01' failed.
//       Converted '12E01' to 120.
//       Converted 'C8' to -56.
//       Attempted conversion of '0x8C' failed.

open System
open System.Globalization

let callTryParse (stringToConvert: string) styles =
    match SByte.TryParse(stringToConvert, styles, CultureInfo.InvariantCulture) with
    | true, number ->
        printfn $"Converted '{stringToConvert}' to {number}."
    | _ ->
        printfn $"Attempted conversion of '{stringToConvert}' failed."

[<EntryPoint>]
let main _ =
    let numericString = "106"
    let styles = NumberStyles.Integer
    callTryParse numericString styles
    
    let numericString = "-106"
    let styles = NumberStyles.None
    callTryParse numericString styles
    
    let numericString = "103.00"
    let styles = NumberStyles.Integer ||| NumberStyles.AllowDecimalPoint
    callTryParse numericString styles
    
    let numericString = "103.72"
    let styles = NumberStyles.Integer ||| NumberStyles.AllowDecimalPoint
    callTryParse numericString styles

    let numericString = "10E-01"
    let styles = NumberStyles.Integer ||| NumberStyles.AllowExponent
    callTryParse numericString styles 
    
    let numericString = "12E-01"
    callTryParse numericString styles
        
    let numericString = "12E01"
    callTryParse numericString styles 
    
    let numericString = "C8"
    callTryParse numericString NumberStyles.HexNumber
    
    let numericString = "0x8C"
    callTryParse numericString NumberStyles.HexNumber
    0

// The example displays the following output:
//       Converted '106' to 106.
//       Attempted conversion of '-106' failed.
//       Converted '103.00' to 103.
//       Attempted conversion of '103.72' failed.
//       Converted '10E-01' to 1.
//       Attempted conversion of '12E-01' failed.
//       Converted '12E01' to 120.
//       Converted 'C8' to -56.
//       Attempted conversion of '0x8C' failed.

Imports System.Globalization

Module StringParsing
   Public Sub Main()
      Dim numericString As String
      Dim styles As NumberStyles
      
      numericString = "106"
      styles = NumberStyles.Integer
      CallTryParse(numericString, styles)
      
      numericString = "-106"
      styles = NumberStyles.None
      CallTryParse(numericString, styles)
      
      numericString = "103.00"
      styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
      CallTryParse(numericString, styles)
      
      numericString = "103.72"
      styles = NumberStyles.Integer Or NumberStyles.AllowDecimalPoint
      CallTryParse(numericString, styles)

      numericString = "10E-01"
      styles = NumberStyles.Integer Or NumberStyles.AllowExponent
      CallTryParse(numericString, styles) 
      
      numericString = "12E-01"
      CallTryParse(numericString, styles)
          
      numericString = "12E01"
      CallTryParse(numericString, styles) 
      
      numericString = "C8"
      CallTryParse(numericString, NumberStyles.HexNumber)
      
      numericString = "0x8C"
      CallTryParse(numericString, NumberStyles.HexNumber)
   End Sub
   
   Private Sub CallTryParse(stringToConvert As String, styles AS NumberStyles)
      Dim number As SByte
      Dim result As Boolean = SByte.TryParse(stringToConvert, styles, _
                                             CultureInfo.InvariantCulture, number)
      If result Then
         Console.WriteLine("Converted '{0}' to {1}.", stringToConvert, number)
      Else
         Console.WriteLine("Attempted conversion of '{0}' failed.", _
                           Convert.ToString(stringToConvert))
      End If                                                                           
   End Sub
End Module
' The example displays the following output to the console:
'       Converted '106' to 106.
'       Attempted conversion of '-106' failed.
'       Converted '103.00' to 103.
'       Attempted conversion of '103.72' failed.
'       Converted '10E-01' to 1.
'       Attempted conversion of '12E-01' failed.
'       Converted '12E01' to 120.
'       Converted 'C8' to -56.
'       Attempted conversion of '0x8C' failed.

Remarks

The TryParse(String, NumberStyles, IFormatProvider, SByte) method is like the Parse(String, NumberStyles, IFormatProvider) method, except that it does not throw an exception if the conversion fails. This method eliminates the need to use exception handling to test for a FormatException if value is invalid and cannot be parsed successfully.

The style parameter defines the style elements (such as white space or a positive or negative sign) that are allowed in the value parameter for the parse operation to succeed. It must be a combination of bit flags from the NumberStyles enumeration. Depending on the value of style, the value parameter may include the following elements:

[ws_][$_][_sign_][digits,]_digits_[._fractional_digits_][E[_sign_]_exponential_digits_][_ws_]

If the style parameter includes AllowHexSpecifier, the value parameter may include the following elements:

[_ws_]_hexdigits_[_ws_]

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

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 decimal digits only (which corresponds to the NumberStyles.None flag) always parses successfully. Most of the remaining NumberStyles members control elements that may be present, but are not required to be present, in this input string. The following table indicates how individual NumberStyles members affect the elements that may be present in value.

If the NumberStyles.AllowHexSpecifier flag is used, value must be a hexadecimal value. Valid hexadecimal digits are 0-9, a-f, and A-F. The only other flags that can be present in style are NumberStyles.AllowLeadingWhite and NumberStyles.AllowTrailingWhite. (The NumberStyles enumeration has a composite style, HexNumber, that includes both white-space flags.)

Note

If value is the string representation of a hexadecimal number, it cannot be preceded by any decoration (such as 0x or &h) that differentiates it as a hexadecimal number. This causes the conversion to fail.

The provider parameter is an IFormatProvider implementation. Its GetFormat method returns a NumberFormatInfo object that provides culture-specific information about the format of value. The provider parameter can be any one of the following:

• 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.
• A NumberFormatInfo object that provides numeric formatting information. (Its implementation of GetFormat just returns itself.)
• A custom object that implements IFormatProvider. Its GetFormat method instantiates and returns the NumberFormatInfo object that provides formatting information.

If provider is null, the NumberFormatInfo object for the current culture is used.

See also

• Parse(String, NumberStyles, IFormatProvider)
• Parsing Numeric Strings in .NET

Applies to