Double.Parse Method (String, NumberStyles)

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 a combination of Float combined with AllowThousands.

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.

Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
   ' Set current thread culture to en-US.
   Thread.CurrentThread.CurrentCulture = New CultureInfo("en-US")

   Dim value As String
   Dim styles As NumberStyles

   ' Parse a string in exponential notation with only the AllowExponent flag. 
   value = "-1.063E-02"
   styles = NumberStyles.AllowExponent
   ShowNumericValue(outputBlock, value, styles)

   ' Parse a string in exponential notation
   ' with the AllowExponent and Number flags.
   styles = NumberStyles.AllowExponent Or NumberStyles.Number
   ShowNumericValue(outputBlock, value, styles)

   ' Parse a currency value with leading and trailing white space, and
   ' white space after the U.S. currency symbol.
   value = " $ 6,164.3299  "
   styles = NumberStyles.Number Or NumberStyles.AllowCurrencySymbol
   ShowNumericValue(outputBlock, value, styles)

   ' Parse negative value with thousands separator and decimal.
   value = "(4,320.64)"
   styles = NumberStyles.AllowParentheses Or NumberStyles.AllowTrailingSign _
            Or NumberStyles.Float
   ShowNumericValue(outputBlock, value, styles)

   styles = NumberStyles.AllowParentheses Or NumberStyles.AllowTrailingSign _
            Or NumberStyles.Float Or NumberStyles.AllowThousands
   ShowNumericValue(outputBlock, value, styles)
End Sub

Private Sub ShowNumericValue(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal value As String, ByVal styles As NumberStyles)
   Dim number As Double
   Try
      number = Double.Parse(value, styles)
      outputBlock.Text &= String.Format("Converted '{0}' using {1} to {2}.", _
                        value, styles.ToString(), number) & vbCrLf
   Catch e As FormatException
      outputBlock.Text &= String.Format("Unable to parse '{0}' with styles {1}.", _
                        value, styles.ToString()) & vbCrLf
   End Try
   outputBlock.Text &= vbCrLf
End Sub
' The example displays the following output:
'    Unable to parse '-1.063E-02' with styles AllowExponent.
'    
'    Converted '-1.063E-02' using AllowTrailingSign, AllowThousands, Float to -0.01063.
'    
'    Converted ' $ 6,164.3299  ' using Number, AllowCurrencySymbol to 6164.3299.
'    
'    Unable to parse '(4,320.64)' with styles AllowTrailingSign, AllowParentheses, Float.
'    
'    Converted '(4,320.64)' using AllowTrailingSign, AllowParentheses, AllowThousands, Float to -4320.64.   

public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
   // Set current thread culture to en-US.
   Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");

   string value;
   NumberStyles styles;

   // Parse a string in exponential notation with only the AllowExponent flag. 
   value = "-1.063E-02";
   styles = NumberStyles.AllowExponent;
   ShowNumericValue(outputBlock, value, styles);

   // Parse a string in exponential notation
   // with the AllowExponent and Number flags.
   styles = NumberStyles.AllowExponent | NumberStyles.Number;
   ShowNumericValue(outputBlock, value, styles);

   // Parse a currency value with leading and trailing white space, and
   // white space after the U.S. currency symbol.
   value = " $ 6,164.3299  ";
   styles = NumberStyles.Number | NumberStyles.AllowCurrencySymbol;
   ShowNumericValue(outputBlock, value, styles);

   // Parse negative value with thousands separator and decimal.
   value = "(4,320.64)";
   styles = NumberStyles.AllowParentheses | NumberStyles.AllowTrailingSign |
            NumberStyles.Float;
   ShowNumericValue(outputBlock, value, styles);

   styles = NumberStyles.AllowParentheses | NumberStyles.AllowTrailingSign |
            NumberStyles.Float | NumberStyles.AllowThousands;
   ShowNumericValue(outputBlock, value, styles);
}

private static void ShowNumericValue(System.Windows.Controls.TextBlock outputBlock, string value, NumberStyles styles)
{
   double number;
   try
   {
      number = Double.Parse(value, styles);
      outputBlock.Text += String.Format("Converted '{0}' using {1} to {2}.",
                        value, styles.ToString(), number) + "\n";
   }
   catch (FormatException)
   {
      outputBlock.Text += String.Format("Unable to parse '{0}' with styles {1}.",
                        value, styles.ToString()) + "\n";
   }
   outputBlock.Text += "\n";
}
// The example displays the following output:
//    Unable to parse '-1.063E-02' with styles AllowExponent.
//    
//    Converted '-1.063E-02' using AllowTrailingSign, AllowThousands, Float to -0.01063.
//    
//    Converted ' $ 6,164.3299  ' using Number, AllowCurrencySymbol to 6164.3299.
//    
//    Unable to parse '(4,320.64)' with styles AllowTrailingSign, AllowParentheses, Float.
//    
//    Converted '(4,320.64)' using AllowTrailingSign, AllowParentheses, AllowThousands, Float to -4320.64.