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UInt64.TryParse Method (String, UInt64%)

Updated: September 2009

Tries to convert the string representation of a number to its 64-bit unsigned integer equivalent. A return value indicates whether the conversion succeeded or failed.

This API is not CLS-compliant. The CLS-compliant alternative is Parse(String).

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

public static bool TryParse(
	string s,
	out ulong result


Type: System.String

A string that represents the number to convert.

Type: System.UInt64%

When this method returns, contains the 64-bit unsigned integer value that is 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, is not of the correct format, or represents a number less than UInt64.MinValue or greater than MaxValue. This parameter is passed uninitialized.

Return Value

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

The TryParse(String, UInt64) method is like the Parse(String) 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 s is invalid and cannot be successfully parsed.

The s parameter should be the string representation of a decimal number in the following form:


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




Optional white space.


An optional sign. Valid sign characters are determined by the NumberFormatInfo.NegativeSign and NumberFormatInfo.PositiveSign properties of the current culture.


A sequence of decimal digits ranging from 0 to 9.

The s parameter is interpreted by using the NumberStyles.Integer style. In addition to the decimal digits, only leading and trailing spaces with a leading sign are allowed. To explicitly define the style elements with the culture-specific formatting information that can be present in s, call the TryParse(String, NumberStyles, IFormatProvider, UInt64) method.


The string specified by the s parameter cannot contain any group separators or decimal separator, and it cannot have a fractional portion.

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

This overload interprets all digits in the s parameter as decimal digits. To parse the string representation of a hexadecimal number, call the TryParse(String, NumberStyles, IFormatProvider, UInt64) overload instead.

The following example calls the TryParse(String, UInt64) method once for each element in a string array.

string[] numericStrings = { "1293.8", "+1671.7", "28347.", 
                            "   33113684  ", "(0)", "-0", "+1293617", 
                            "18-", "119870", "31,024", "  3127094 ",  
                            "00700000" };
ulong number;
foreach (string numericString in numericStrings)
   if (UInt64.TryParse(numericString, out number)) 
      Console.WriteLine("Converted '{0}' to {1}.", numericString, number);
      Console.WriteLine("Cannot convert '{0}' to a UInt64.", numericString);
// The example displays the following output: 
//       Cannot convert '1293.8' to a UInt64. 
//       Cannot convert '+1671.7' to a UInt64. 
//       Cannot convert '28347.' to a UInt64. 
//       Converted '   33113684  ' to 33113684. 
//       Cannot convert '(0)' to a UInt64. 
//       Converted '-0' to 0. 
//       Converted '+1293617' to 1293617. 
//       Cannot convert '18-' to a UInt64. 
//       Converted '119870' to 119870. 
//       Cannot convert '31,024' to a UInt64. 
//       Converted '  3127094 ' to 3127094. 
//       Converted '0070000' to 70000.

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.

.NET Framework

Supported in: 3.5, 3.0, 2.0




September 2009

Revised extensively.

Information enhancement.