Int32.Parse Method (String, IFormatProvider)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Converts the string representation of a number in a specified culture-specific format to its 32-bit signed integer equivalent.
Assembly: mscorlib (in mscorlib.dll)
'Declaration Public Shared Function Parse ( _ s As String, _ provider As IFormatProvider _ ) As Integer
Parameters
- s
- Type: System.String
A string containing a number to convert.
- provider
- Type: System.IFormatProvider
An IFormatProvider that supplies culture-specific formatting information about s.
| Exception | Condition |
|---|---|
| ArgumentNullException | s is Nothing. |
| FormatException | s is not of the correct format. |
| OverflowException | s represents a number less than MinValue or greater than MaxValue. |
This overload of the Parse(String, IFormatProvider) method is typically used to convert text that can be formatted in a variety of ways to an Int32 value. For example, it can be used to convert the text entered by a user into an HTML text box to a numeric value.
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 decimal digits, only leading and trailing spaces together with a leading sign are allowed. To explicitly define the style elements that can be present in s, use the Int32.Parse(String, NumberStyles, IFormatProvider) method.
The provider parameter is an IFormatProvider implementation, such as a NumberFormatInfo or CultureInfo object. The provider parameter supplies culture-specific information about the format of s. If provider is Nothing, the NumberFormatInfo object for the current culture is used.
The following example illustrates the use of the Parse(String, IFormatProvider) method to parse a string. The method first attempts to parse the string using the current culture. If the parse operation fails, it attempts to parse the string using a neutral culture. If this parse operation fails, it attempts to parse the string using the invariant culture. Note that, in a real application, the Int32.TryParse(String, NumberStyles, IFormatProvider, Int32) method is better suited for this purpose.
Public Function GetInteger(value As String) As Integer Dim culture As CultureInfo = Nothing Dim number As Integer ' Throw exception if string is empty. If String.IsNullOrEmpty(value) Then _ Throw New ArgumentNullException("The input string is invalid.") ' Determine if value can be parsed using current culture. Try culture = CultureInfo.CurrentCulture number = Integer.Parse(value, culture) Return number Catch End Try ' If Parse operation fails, see if there's a neutral culture. Try culture = culture.Parent number = Integer.Parse(value, culture) Return number Catch End Try ' If there is no neutral culture or if parse operation fails, use ' the invariant culture. culture = CultureInfo.InvariantCulture Try number = Integer.Parse(value, culture) Return number ' All attempts to parse the string have failed; rethrow the exception. Catch e As FormatException Throw New FormatException(String.Format("Unable to parse '{0}'.", value), _ e) End Try End Function