C# | Double.ToString() Method | Set – 2

Double.ToString() Method is used to convert the numeric value of the current instance to its equivalent string representation. There are 4 methods in the overload list of this method as follows:

• ToString(String) Method
• ToString() Method
• ToString(IFormatProvider) Method
• ToString(String, IFormatProvider) Method

Here, we will discuss the last two methods.

ToString(IFormatProvider) Method

This method is used to convert the numeric value of the current instance to its equivalent string representation using the specified culture-specific format information.
Syntax:

public string ToString (IFormatProvider provider);

Parameters: This method takes an object of type IFormatProvider which supplies culture-specific formatting information.
Return Value: This method returns the string representation of the value of the current instance in the format specified by the provider parameter.
Example:

csharp

// C# program to demonstrate
// Double.ToString(IFormatProvider)
// Method
using System;
using System.Globalization;

class GFG {

    // Main Method
    public static void Main()
    {
        // declaring and initializing Double value
        double d1 = 568912.4587d;

        // creating and initializing
        // the object of CultureInfo
        CultureInfo provider = new CultureInfo("en-us");

        // using the method
        string value = d1.ToString(provider);

        // Display the value
        Console.WriteLine("The Value is {0} and provider is {1}",
                                           value, provider.Name);
    }
}

Output:

The Value is 568912.4587 and provider is en-US

Double.ToString(String, IFormatProvider) Method

This method is used to convert the numeric value of the current instance to its equivalent string representation using the specified format and culture-specific formatting information.
Syntax:

public string ToString (string format, IFormatProvider provider);

Parameters:

format: It is a numeric format string. 
provider: It is an object that supplies culture-specific formatting information. 

Return Value: This method returns the string representation of the value of the current instance in the format specified by the provider parameter.
Example:

csharp

// C# program to demonstrate the
// Double.ToString(String, IFormatProvider)
// Method
using System;
using System.Globalization;

class GFG {

    // Main Method
    public static void Main()
    {

        // declaring and initializing Double value
        double d1 = 7876312.7823d;

        // creating and initializing
        // the object of CultureInfo
        CultureInfo provider = new CultureInfo("fr-FR");

        // declaring and initializing format
        string format = "E04";

        // using the method
        string val = d1.ToString(format, provider);

        // Displaying the details
        Console.WriteLine("The value is {0}",val);
        Console.WriteLine("The Format is {0}",format);
        Console.WriteLine("The Provider is {0}", provider.Name);
    }
}

Output:

The value is 7,8763E+006
The Format is E04
The Provider is fr-FR

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.double.tostring?view=netframework-4.7.2