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Double::ToString Method (IFormatProvider^)

.NET Framework (current version)
 

Converts the numeric value of this instance to its equivalent string representation using the specified culture-specific format information.

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

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public:
virtual String^ ToString(
	IFormatProvider^ provider
) sealed

Parameters

provider
Type: System::IFormatProvider^

An object that supplies culture-specific formatting information.

Return Value

Type: System::String^

The string representation of the value of this instance as specified by provider.

Implements

IConvertible::ToString(IFormatProvider^)

The ToString(IFormatProvider^) method formats a Double value in the default ("G", or general) format of a specified culture. If you want to specify a different format or culture, use the other overloads of the ToString method, as follows:

To use format

For culture

Use the overload

Default ("G") format

Default (current)

ToString()

A specific format or precision

Default (current) culture

ToString(String^)

A specific format or precision

A specific culture

ToString(String^, IFormatProvider^)

The return value can be PositiveInfinitySymbol, NegativeInfinitySymbol, NaNSymbol, or a string of the form:

[sign]integral-digits[.[fractional-digits]][e[sign]exponential-digits]

Optional elements are framed in square brackets ([ and ]). Elements that contain the term "digits" consist of a series of numeric characters ranging from 0 to 9. The elements listed in the following table are supported.

Element

Description

sign

A negative sign or positive sign symbol.

integral-digits

A series of digits specifying the integral part of the number. Integral-digits can be absent if there are fractional-digits.

'.'

A culture-specific decimal point symbol.

fractional-digits

A series of digits specifying the fractional part of the number.

'e'

A lowercase character 'e', indicating exponential (scientific) notation.

exponential-digits

A series of digits specifying an exponent.

Some examples of the return value are "100", "-123,456,789", "123.45e+6", "500", "3.1416", "600", "-0.123", and "-Infinity".

This instance is formatted with the general numeric format specifier ("G").

The .NET Framework provides extensive formatting support, which is described in greater detail in the following formatting topics:

The provider parameter is an IFormatProvider implementation whose GetFormat method returns a NumberFormatInfo object. Typically, provider is a CultureInfo object or a NumberFormatInfo object. The provider parameter supplies culture-specific information used in formatting. If provider is null, the return value is formatted using the NumberFormatInfo object for the current culture.

The following example displays the string representation of two Double values using CultureInfo objects that represent several different cultures.

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No code example is currently available or this language may not be supported.

The following example illustrates the use of ToString, taking a String and an IFormatProvider as parameters.

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public ref class Temperature: public IFormattable
{
   // IFormattable.ToString implementation.
public:
   virtual String^ ToString( String^ format, IFormatProvider^ provider )
   {
      if ( format != nullptr )
      {
         if ( format->Equals( "F" ) )
         {
            return String::Format( "{0}'F", this->Value.ToString() );
         }

         if ( format->Equals( "C" ) )
         {
            return String::Format( "{0}'C", this->Celsius.ToString() );
         }
      }

      return m_value.ToString( format, provider );
   }

protected:
   // The value holder
   double m_value;

public:
   property double Value 
   {
      double get()
      {
         return m_value;
      }
      void set( double value )
      {
         m_value = value;
      }
   }

   property double Celsius 
   {
      double get()
      {
         return (m_value - 32.0) / 1.8;
      }
      void set( double value )
      {
         m_value = 1.8 * value + 32.0;
      }
   }
};

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
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
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