Int64.Parse Method (String, NumberStyles, IFormatProvider)


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Converts the string representation of a number in a specified style and culture-specific format to its 64-bit signed integer equivalent.

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

public static long Parse(
	string s,
	NumberStyles style,
	IFormatProvider provider


Type: System.String

A string containing a number to convert.

Type: System.Globalization.NumberStyles

A bitwise combination of enumeration values that indicates the style elements that can be present in s. A typical value to specify is Integer.

Type: System.IFormatProvider

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

Return Value

Type: System.Int64

A 64-bit signed integer equivalent to the number specified in s.

Exception Condition

s is null.


style is not a NumberStyles value.


style is not a combination of AllowHexSpecifier and HexNumber values.


s is not in a format compliant with style.


s represents a number less than MinValue or greater than MaxValue.


style supports fractional digits, but s includes non-zero fractional digits.

The style parameter defines the style elements (such as white space or the positive sign) that are allowed in the s 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 s parameter may include the following elements:


Or, if style includes AllowHexSpecifier:


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




Optional white space. White space can appear at the beginning of s if style includes the NumberStyles.AllowLeadingWhite flag, and 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.CurrencyPositivePattern property of the NumberFormatInfo object returned by the GetFormat method of the provider parameter. The currency symbol can appear in s if style includes the NumberStyles.AllowCurrencySymbol flag.


An optional sign. The sign can appear at the beginning of s if style includes the NumberStyles.AllowLeadingSign flag or 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.




A sequence of digits from 0 through 9.


A culture-specific thousands separator symbol. The thousands separator of the culture specified by provider can appear in s if style includes the NumberStyles.AllowThousands flag.


A culture-specific decimal point symbol. The decimal point symbol of the culture specified by provider can appear in s if style includes the NumberStyles.AllowDecimalPoint flag.

Only the digit 0 can appear as a fractional digit for the parse operation to succeed; if fractional_digits includes any other digit, an OverflowException is thrown.


The 'e' or 'E' character, which indicates that the value is represented in exponential notation. The s parameter can represent a number in exponential notation if style includes the NumberStyles.AllowExponent flag.


A sequence of hexadecimal digits from 0 through f, or 0 through F.

A string with decimal digits only (which corresponds to the NumberStyles.None style) always parses successfully if it is in the range of the Int64 type. Most of the remaining NumberStyles members control elements that may be 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 s.

Non-composite NumberStyles values

Elements permitted in s in addition to digits


Decimal digits only.


The decimal point ( . ) and fractional-digits elements. However, fractional-digits must consist of only one or more 0 digits or an OverflowException is thrown.


The s parameter can also use exponential notation.


The ws element at the beginning of s.


The ws element at the end of s.


A sign can appear before digits.


A sign can appear after digits.


The sign element in the form of parentheses enclosing the numeric value.


The thousands separator ( , ) element.


The $ element.

If the NumberStyles.AllowHexSpecifier flag is used, s must be a hexadecimal value without a prefix. For example, "C9AF3" parses successfully, but "0xC9AF3" does not. The only other flags that can be present in style are NumberStyles.AllowLeadingWhite and NumberStyles.AllowTrailingWhite. (The NumberStyles enumeration has a composite number style, NumberStyles.HexNumber, that includes both white space flags.)

The provider parameter is an IFormatProvider implementation, such as a NumberFormatInfo or CultureInfo object. The provider parameter supplies culture-specific information used in parsing. If provider is null, the NumberFormatInfo for the current culture is used.

The following example uses a variety of style and provider parameters to parse the string representations of Int64 values. It also illustrates some of the different ways the same string can be interpreted depending on the culture whose formatting information is used for the parsing operation.

using System;
using System.Globalization;

public class ParseInt64
   public static void Main()
      Convert("12,000", NumberStyles.Float | NumberStyles.AllowThousands, 
              new CultureInfo("en-GB"));
      Convert("12,000", NumberStyles.Float | NumberStyles.AllowThousands,
              new CultureInfo("fr-FR"));
      Convert("12,000", NumberStyles.Float, new CultureInfo("en-US"));

      Convert("12 425,00", NumberStyles.Float | NumberStyles.AllowThousands,
              new CultureInfo("sv-SE"));
      Convert("12,425.00", NumberStyles.Float | NumberStyles.AllowThousands,
      Convert("631,900", NumberStyles.Integer | NumberStyles.AllowDecimalPoint, 
              new CultureInfo("fr-FR"));
      Convert("631,900", NumberStyles.Integer | NumberStyles.AllowDecimalPoint,
              new CultureInfo("en-US"));
      Convert("631,900", NumberStyles.Integer | NumberStyles.AllowThousands,
              new CultureInfo("en-US"));

   private static void Convert(string value, NumberStyles style, 
                               IFormatProvider provider)
         long number = Int64.Parse(value, style, provider);
         Console.WriteLine("Converted '{0}' to {1}.", value, number);
      catch (FormatException)
         Console.WriteLine("Unable to convert '{0}'.", value);
      catch (OverflowException)
         Console.WriteLine("'{0}' is out of range of the Int64 type.", value);   
// This example displays the following output to the console:
//       Converted '12,000' to 12000.
//       Converted '12,000' to 12.
//       Unable to convert '12,000'.
//       Converted '12 425,00' to 12425.
//       Converted '12,425.00' to 12425.
//       '631,900' is out of range of the Int64 type.
//       Unable to convert '631,900'.
//       Converted '631,900' to 631900.

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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