Int32.TryParse Method (String, Int32) (System)

TryParse Method (String, Int32)

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Microsoft Visual Studio 2008/.NET Framework 3.5

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.NET Framework Class Library

Int32..::.TryParse Method (String, Int32%)

Updated: July 2008

Converts the string representation of a number to its 32-bit signed integer equivalent. A return value indicates whether the conversion succeeded.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

Syntax

Visual Basic (Declaration)

Public Shared Function TryParse ( _
    s As String, _
    <OutAttribute> ByRef result As Integer _
) As Boolean

Visual Basic (Usage)

Dim s As String
Dim result As Integer
Dim returnValue As Boolean

returnValue = Integer.TryParse(s, result)

public static bool TryParse(
    string s,
    out int result
)

Visual C++

public:
static bool TryParse(
    String^ s, 
    [OutAttribute] int% result
)

JScript

public static function TryParse(
    s : String, 
    result : int
) : boolean

Parameters

s: Type: System..::.String
A string containing a number to convert.

result: Type: System..::.Int32%
When this method returns, contains the 32-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 nullNothingnullptra null reference (Nothing in Visual Basic), is not of the correct format, or represents a number less than MinValue or greater than MaxValue. This parameter is passed uninitialized.

Return Value

Type: System..::.Boolean
true if s was converted successfully; otherwise, false.

Remarks

The TryParse method is like the Parse method, except the TryParse method does not throw an exception if the conversion fails. 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 contains a number of the form:

[ws][sign]digits[ws]

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

Element	Description
ws	Optional white space.
sign	An optional sign.
digits	A sequence of digits ranging from 0 to 9.

The s parameter is interpreted using the NumberStyles..::.Integer style. In addition to the decimal digits, only leading and trailing spaces together with a leading sign are allowed. To explicitly define the style elements together with the culture-specific formatting information that can be present in s, use the Int32..::.TryParse(String, NumberStyles, IFormatProvider, Int32%) method.

The s parameter is parsed using the formatting information in a NumberFormatInfo object initialized for the current system culture. For more information, see CurrentInfo.

This overload of the TryParse method interprets all digits in the s parameter as decimal digits. To parse the string representation of a hexadecimal number, call the Int32..::.TryParse(String, NumberStyles, IFormatProvider, Int32%) overload.

Examples

The following example calls the Int32..::.TryParse(String, Int32%) method with a number of different string values.

Visual Basic

Module StringParsing
   Public Sub Main()
      TryToParse(Nothing)
      TryToParse("160519")
      TryToParse("9432.0")
      TryToParse("16,667")
      TryToParse("   -322   ")
      TryToParse("+4302")
      TryToParse("(100)")
      TryToParse("01FA")
   End Sub

   Private Sub TryToParse(value As String)
      Dim number As Integer
      Dim result As Boolean = Int32.TryParse(value, number)
      If result Then
         Console.WriteLine("Converted '{0}' to {1}.", value, number)
      Else
         If value Is Nothing Then value = "" 
         Console.WriteLine("Attempted conversion of '{0}' failed.", value)
      End If     
   End Sub
End Module
' The example displays the following output to the console:
'       Attempted conversion of '' failed.
'       Converted '160519' to 160519.
'       Attempted conversion of '9432.0' failed.
'       Attempted conversion of '16,667' failed.
'       Converted '   -322   ' to -322.
'       Converted '+4302' to 4302.
'       Attempted conversion of '(100)' failed.
'       Attempted conversion of '01FA' failed.

using System;

public class StringParsing
{
   public static void Main()
   {
      TryToParse(null);
      TryToParse("160519");
      TryToParse("9432.0");
      TryToParse("16,667");
      TryToParse("   -322   ");
      TryToParse("+4302");
      TryToParse("(100);");
      TryToParse("01FA");
   }

   private static void TryToParse(string value)
   {
      int number;
      bool result = Int32.TryParse(value, out number);
      if (result)
      {
         Console.WriteLine("Converted '{0}' to {1}.", value, number);         
      }
      else
      {
         if (value == null) value = ""; 
         Console.WriteLine("Attempted conversion of '{0}' failed.", value);
      }
   }
}
// The example displays the following output to the console:
//       Attempted conversion of '' failed.
//       Converted '160519' to 160519.
//       Attempted conversion of '9432.0' failed.
//       Attempted conversion of '16,667' failed.
//       Converted '   -322   ' to -322.
//       Converted '+4302' to 4302.
//       Attempted conversion of '(100);' failed.
//       Attempted conversion of '01FA' failed.

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information