Double.Parse Method (String, NumberStyles, IFormatProvider)

Converts the string representation of a number in a specified style and culture-specific format to its double-precision floating-point number equivalent.

Parameters

• s
  Type: System.String
  A string that contains a number to convert.

• style
  Type: System.Globalization.NumberStyles
  A bitwise combination of enumeration values that indicate the style elements that can be present in s. A typical value to specify is Float combined with AllowThousands.

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

Return Value

Type: System.Double
A double-precision floating-point number that is equivalent to the numeric value or symbol specified in s.

Dim value As String
value = Double.MinValue.ToString()
Try
 outputBlock.Text += Double.Parse(value).ToString() + vbCrLf
Catch e As OverflowException
 outputBlock.Text += String.Format("{0} is outside the range of the Double type.", _
 value) + vbCrLf
End Try
value = Double.MaxValue.ToString()
Try
 outputBlock.Text += Double.Parse(value).ToString() + vbCrLf
Catch e As OverflowException
 outputBlock.Text += String.Format("{0} is outside the range of the Double type.", _
 value) + vbCrLf
End Try
' The example displays the following output:
' -1.79769313486232E+308 is outside the range of the Double type.
' 1.79769313486232E+308 is outside the range of the Double type. 

 string value;
 value = Double.MinValue.ToString();
 try {
 outputBlock.Text += Double.Parse(value) + "\n";
 } 
 catch (OverflowException) {
 outputBlock.Text += String.Format("{0} is outside the range of the Double type.\n",
 value);
 }
 value = Double.MaxValue.ToString();
 try {
 outputBlock.Text += Double.Parse(value) + "\n";
 }
 catch (OverflowException) {
 outputBlock.Text += String.Format("{0} is outside the range of the Double type.\n",
 value);
 }
// The example displays the following output:
// -1.79769313486232E+308 is outside the range of the Double type.
// 1.79769313486232E+308 is outside the range of the Double type.

Imports System.Globalization
Public Class Temperature
 ' Parses the temperature from a string. Temperature scale is 
 ' indicated by 'F (for Fahrenheit) or 'C (for Celcius) at the end
 ' of the string.
 Public Shared Function Parse(ByVal s As String, ByVal styles As NumberStyles, _
 ByVal provider As IFormatProvider) As Temperature
 Dim temp As New Temperature()
 If s.TrimEnd(Nothing).EndsWith("'F") Then
 temp.Value = Double.Parse(s.Remove(s.LastIndexOf("'"c), 2), _
 styles, provider)
 Else
 If s.TrimEnd(Nothing).EndsWith("'C") Then
 temp.Celsius = Double.Parse(s.Remove(s.LastIndexOf("'"c), 2), _
 styles, provider)
 Else
 temp.Value = Double.Parse(s, styles, provider)
 End If
 End If
 Return temp
 End Function
 ' Declare private constructor so Temperature so only Parse method can
 ' create a new instance
 Private Sub New()
 End Sub
 Protected m_value As Double
 Public Property Value() As Double
 Get
 Return m_value
 End Get
 Private Set(ByVal value As Double)
 m_value = value
 End Set
 End Property
 Public Property Celsius() As Double
 Get
 Return (m_value - 32) / 1.8
 End Get
 Private Set(ByVal value As Double)
 m_value = value * 1.8 + 32
 End Set
 End Property
 Public ReadOnly Property Fahrenheit() As Double
 Get
 Return m_value
 End Get
 End Property
End Class
Public Module Example
 Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
 Dim value As String
 Dim styles As NumberStyles
 Dim provider As IFormatProvider
 Dim temp As Temperature
 value = "25,3'C"
 styles = NumberStyles.Float
 provider = New CultureInfo("fr-FR")
 temp = Temperature.Parse(value, styles, provider)
 outputBlock.Text += String.Format("{0} degrees Fahrenheit equals {1} degrees Celsius.", _
 temp.Fahrenheit, temp.Celsius) + vbCrLf
 value = " (40) 'C"
 styles = NumberStyles.AllowLeadingWhite Or NumberStyles.AllowTrailingWhite _
 Or NumberStyles.AllowParentheses
 provider = NumberFormatInfo.InvariantInfo
 temp = Temperature.Parse(value, styles, provider)
 outputBlock.Text += String.Format("{0} degrees Fahrenheit equals {1} degrees Celsius.", _
 temp.Fahrenheit, temp.Celsius) + vbCrLf
 value = "5,778E03'C" ' Approximate surface temperature of the Sun
 styles = NumberStyles.AllowDecimalPoint Or NumberStyles.AllowThousands Or _
 NumberStyles.AllowExponent
 provider = New CultureInfo("en-GB")
 temp = Temperature.Parse(value, styles, provider)
 outputBlock.Text += String.Format("{0} degrees Fahrenheit equals {1} degrees Celsius.", _
 temp.Fahrenheit.ToString("N"), temp.Celsius.ToString("N")) + vbCrLf
 End Sub
End Module

using System;
using System.Globalization;
public class Temperature
{
 // Parses the temperature from a string. Temperature scale is 
 // indicated by 'F (for Fahrenheit) or 'C (for Celcius) at the end
 // of the string.
 public static Temperature Parse(string s, NumberStyles styles,
 IFormatProvider provider)
 {
 Temperature temp = new Temperature();
 if (s.TrimEnd(null).EndsWith("'F"))
 {
 temp.Value = Double.Parse(s.Remove(s.LastIndexOf((char)39), 2),
 styles, provider);
 }
 else
 {
 if (s.TrimEnd(null).EndsWith("'C"))
 temp.Celsius = Double.Parse(s.Remove(s.LastIndexOf((char)39), 2),
 styles, provider);
 else
 temp.Value = Double.Parse(s, styles, provider);
 }
 return temp;
 }
 // Declare private constructor so Temperature so only Parse method can
 // create a new instance
 private Temperature() { }
 protected double m_value;
 public double Value
 {
 get { return m_value; }
 private set { m_value = value; }
 }
 public double Celsius
 {
 get { return (m_value - 32) / 1.8; }
 private set { m_value = value * 1.8 + 32; }
 }
 public double Fahrenheit
 {
 get { return m_value; }
 }
}
public class Example
{
 public static void Demo(System.Windows.Controls.TextBlock outputBlock)
 {
 string value;
 NumberStyles styles;
 IFormatProvider provider;
 Temperature temp;
 value = "25,3'C";
 styles = NumberStyles.Float;
 provider = new CultureInfo("fr-FR");
 temp = Temperature.Parse(value, styles, provider);
 outputBlock.Text += String.Format("{0} degrees Fahrenheit equals {1} degrees Celsius.",
 temp.Fahrenheit, temp.Celsius) + "\n";
 value = " (40) 'C";
 styles = NumberStyles.AllowLeadingWhite | NumberStyles.AllowTrailingWhite
 | NumberStyles.AllowParentheses;
 provider = NumberFormatInfo.InvariantInfo;
 temp = Temperature.Parse(value, styles, provider);
 outputBlock.Text += String.Format("{0} degrees Fahrenheit equals {1} degrees Celsius.",
 temp.Fahrenheit, temp.Celsius) + "\n";
 value = "5,778E03'C"; // Approximate surface temperature of the Sun
 styles = NumberStyles.AllowDecimalPoint | NumberStyles.AllowThousands |
 NumberStyles.AllowExponent;
 provider = new CultureInfo("en-GB");
 temp = Temperature.Parse(value, styles, provider);
 outputBlock.Text += String.Format("{0} degrees Fahrenheit equals {1} degrees Celsius.",
 temp.Fahrenheit.ToString("N"), temp.Celsius.ToString("N")) + "\n";
 }
}

Double Structure

Parse Overload

System Namespace

ToString

Parsing Numeric Strings