Int32TryParse Method
 

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)

public static bool TryParse(
	string s,
	out int result
)
public:
static bool TryParse(
	String^ s,
	[OutAttribute] int% result
)
static member TryParse : 
        s:string *
        result:int byref -> bool
Public Shared Function TryParse (
	s As String,
	<OutAttribute> ByRef result As Integer
) As Boolean

Parameters

s
Type:

A string containing a number to convert.

result
Type:

When this method returns, contains the 32-bit signed integer value equivalent of 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 StringEmpty, is not of the correct format, or represents a number less than MinValue or greater than MaxValue. This parameter is passed uninitialized; any value originally supplied in result will be overwritten.

Return Value

Type:

true if s was converted successfully; otherwise, false.

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 NumberStylesInteger 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 Int32TryParse method.

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

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 Int32TryParse overload.

The following example calls the Int32TryParse method with a number of different string values.

using System;

public class Example
{
   public static void Main()
   {
      String[] values = { null, "160519", "9432.0", "16,667",
                          "   -322   ", "+4302", "(100);", "01FA" };
      foreach (var value in values) {
         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 == null ? "<null>" : value);
         }
      }
   }
}
// The example displays the following output:
//       Attempted conversion of '<null>' 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.
Module Example
   Public Sub Main()
      Dim values() As String = { Nothing, "160519", "9432.0", "16,667",
                                 "   -322   ", "+4302", "(100);", 
                                 "01FA" }

      For Each value In values
         Dim number As Integer

         Dim result As Boolean = Int32.TryParse(value, number)
         If result Then
            Console.WriteLine("Converted '{0}' to {1}.", value, number)
         Else
            Console.WriteLine("Attempted conversion of '{0}' failed.", 
                              If(value Is Nothing, "<null>", value))
         End If     
      Next
   End Sub
End Module
' The example displays the following output to the console:
'       Attempted conversion of '<null>' 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 namespace System;


   void TryToParse(String^ value)
   {
      Int32 number;
      bool result = Int32::TryParse(value, number);
      if (result) {
         Console::WriteLine("Converted '{0}' to {1}.", value, number);
      }
      else {
         if (value == nullptr) value = "";
         Console::WriteLine("Attempted conversion of '{0}' failed.", value);
      }
   }


void main()
{
      TryToParse(nullptr);
      TryToParse("160519");
      TryToParse("9432.0");
      TryToParse("16,667");
      TryToParse("   -322   ");
      TryToParse("+4302");
      TryToParse("(100);");
      TryToParse("01FA");
}
// The example displays the following output:
//      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.

Some of the strings that the TryParse method is unable to convert in this example are:

  • "9432.0". The conversion fails because the string cannot contain a decimal separator; it must contain integral digits only.

  • "16,667". The conversion fails because the string cannot contain group separators; it must contain integral digits only.

  • "(100)". The conversion fails because the string cannot contain a negative sign other than the one defined by the current culture's and properties.

  • "01FA". The conversion fails because the string cannot contain hexadecimal digits; it must contain decimal digits only.

Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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