Int16.TryParse Method (String, NumberStyles, IFormatProvider, Int16)

.NET Framework (current version)

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Converts the string representation of a number in a specified style and culture-specific format to its 16-bit signed integer equivalent. A return value indicates whether the conversion succeeded or failed.

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

Syntax

C++

public static bool TryParse(
	string s,
	NumberStyles style,
	IFormatProvider provider,
	out short result
)

Parameters

s: Type: System.String
A string containing a number to convert. The string is interpreted using the style specified by style.

style: 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 NumberStyles.Integer.

provider: Type: System.IFormatProvider
An object that supplies culture-specific formatting information about s.

result: Type: System.Int16
When this method returns, contains the 16-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 String.Empty, is not in a format compliant with style, 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: System.Boolean

true if s was converted successfully; otherwise, false.

Exceptions

Exception	Condition
ArgumentException	style is not a NumberStyles value. -or- style is not a combination of AllowHexSpecifier and HexNumber values.

Remarks

The Int16.TryParse(String, NumberStyles, IFormatProvider, Int16) method differs from the Int16.Parse(String, NumberStyles, IFormatProvider) method by returning a Boolean value that indicates whether the parse operation succeeded instead of returning the parsed Int16 value. 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 style parameter defines the style elements (such as white space or a positive or negative 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:

[ws][$][sign][digits,]digits[.fractional_digits][e[sign]digits][ws]

Or, if the style parameter includes NumberStyles.AllowHexSpecifier:

[ws]hexdigits[ws]

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

Element	Description
ws	Optional white space. White space can appear at the beginning of s if style includes the NumberStyles.AllowLeadingWhite flag, or 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 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.
sign	An optional sign.
digits	A sequence of digits from 0 through 9.
,	A culture-specific thousands separator. 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.
fractional_digits	One or more occurrences of the digit 0. Fractional digits can appear in s only if style includes the NumberStyles.AllowDecimalPoint flag.
e	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.
hexdigits	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 flag) always parses successfully. 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
NumberStyles.None	Decimal digits only.
NumberStyles.AllowDecimalPoint	The . and fractional_digits elements. However, fractional_digits must consist of only one or more 0 digits or the method returns false.
NumberStyles.AllowExponent	The s parameter can also use exponential notation. If s represents a number in exponential notation, it must represent an integer within the range of the Int16 data type without a non-zero fractional component.
NumberStyles.AllowLeadingWhite	The ws element at the beginning of s.
NumberStyles.AllowTrailingWhite	The ws element at the end of s.
NumberStyles.AllowLeadingSign	A sign can appear before digits.
NumberStyles.AllowTrailingSign	A sign can appear after digits.
NumberStyles.AllowParentheses	The sign element in the form of parentheses enclosing the numeric value.
NumberStyles.AllowThousands	The , element.
NumberStyles.AllowCurrencySymbol	The $ element.
NumberStyles.Currency	All elements. The s parameter cannot represent a hexadecimal number or a number in exponential notation.
NumberStyles.Float	The ws element at the beginning or end of s, sign at the beginning of s, and the . symbol. The s parameter can also use exponential notation.
NumberStyles.Number	The ws, sign, thousands separator (,), and decimal point (.) elements.
NumberStyles.Any	All styles, except s cannot represent a hexadecimal number.

If the NumberStyles.AllowHexSpecifier flag is used, s must be a hexadecimal value without a prefix. For example, "9AF3" parses successfully, but "0x9AF3" does not. The only other flags that can be present in style are NumberStyles.AllowLeadingWhite and NumberStyles.AllowTrailingWhite. (The NumberStyles enumeration has a composite style, NumberStyles.HexNumber, that includes both white space flags.)

The provider parameter is an IFormatProvider implementation, such as a CultureInfo object or a NumberFormatInfo object, whose GetFormat method returns a NumberFormatInfo object. The NumberFormatInfo object provides culture-specific information about the format of s. If provider is null, the NumberFormatInfo object for the current culture is used.

Examples

The following example calls the Int16.TryParse(String, NumberStyles, IFormatProvider, Int16) method with a number of different string values.

using System;
using System.Globalization;

public class StringParsing
{
   public static void Main()
   {
      string numericString;
      NumberStyles styles;

      numericString = "10677";
      styles = NumberStyles.Integer;
      CallTryParse(numericString, styles);

      numericString = "-30677";
      styles = NumberStyles.None;
      CallTryParse(numericString, styles);

      numericString = "10345.00";
      styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
      CallTryParse(numericString, styles);

      numericString = "10345.72";
      styles = NumberStyles.Integer | NumberStyles.AllowDecimalPoint;
      CallTryParse(numericString, styles);

      numericString = "22,593"; 
      styles = NumberStyles.Integer | NumberStyles.AllowThousands;
      CallTryParse(numericString, styles);

      numericString = "12E-01";
      styles = NumberStyles.Integer | NumberStyles.AllowExponent;
      CallTryParse(numericString, styles); 

      numericString = "12E03";
      CallTryParse(numericString, styles); 

      numericString = "80c1";
      CallTryParse(numericString, NumberStyles.HexNumber);

      numericString = "0x80C1";
      CallTryParse(numericString, NumberStyles.HexNumber);      
   }

   private static void CallTryParse(string stringToConvert, NumberStyles styles)
   {
      short number;
      bool result = Int16.TryParse(stringToConvert, styles, 
                                   CultureInfo.InvariantCulture, out number);
      if (result)
         Console.WriteLine("Converted '{0}' to {1}.", stringToConvert, number);
      else
         Console.WriteLine("Attempted conversion of '{0}' failed.", 
                           Convert.ToString(stringToConvert));
   }
}
// The example displays the following output to the console:
//       Converted '10677' to 10677.
//       Attempted conversion of '-30677' failed.
//       Converted '10345.00' to 10345.
//       Attempted conversion of '10345.72' failed.
//       Converted '22,593' to 22593.
//       Attempted conversion of '12E-01' failed.
//       Converted '12E03' to 12000.
//       Converted '80c1' to -32575.
//       Attempted conversion of '0x80C1' failed.

Version Information

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