C# | Convert.ToSingle(String, IFormatProvider) Method

This method is used to converts the specified string representation of a number to an equivalent single-precision floating-point number, using the specified culture-specific formatting information.
Syntax:

public static float ToSingle (string value, IFormatProvider provider);

Parameters:

• value: It is a string that contains the number to convert.
• provider: It is an object that supplies culture-specific formatting information.

Return Value: This method returns a single-precision floating-point number that is equivalent to the number in value, or 0 (zero) if value is null.
Exceptions:

• FormatException: If the value does not consist of an optional sign followed by a sequence of digits (0 through 9).
• OverFlowException: If the value represents a number that is less than MinValue or greater than MaxValue.

Below programs illustrate the use of Convert.ToSingle(String, IFormatProvider) Method: 
Example 1: 

csharp

// C# program to demonstrate the
// Convert.ToSingle() Method
using System;
using System.Globalization;

class GFG {

// Main Method
public static void Main()
{

    try {

        // creating object of CultureInfo
        CultureInfo cultures = new CultureInfo("en-US");

        // declaring and initializing String array
        string[] values = {"123.45", "+12.345",
                                    "-1234.5"};

        // calling get() Method
        Console.Write("Converted float value"
             + " from a specified string ");

        for (int j = 0; j < values.Length; j++)
        {
            get(values[j], cultures);
        }
    }

    catch (FormatException e)
    {
        Console.WriteLine("\n");
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }

    catch (OverflowException e)
    {
        Console.WriteLine("\n");
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
}

// Defining get() method
public static void get(string s,
           CultureInfo cultures)
{

    // converting string to specified float
    float val = Convert.ToSingle(s, cultures);

    // display the converted float value
    Console.Write(" {0}, ", val);
}
}

Output

Converted float value from a specified string  123.45,  12.345,  -1234.5, 

Example 2: For FormatException

csharp

// C# program to demonstrate the
// Convert.ToSingle() Method
using System;
using System.Globalization;

class GFG {

// Main Method
public static void Main()
{
    try {

        // creating object of CultureInfo
        CultureInfo cultures = new CultureInfo("en-US");

        // declaring and initializing String array
        string[] values = {"12.345", "+1234.5",
                                    "-123.45"};

        // calling get() Method
        Console.Write("Converted float value"
                + " of specified strings: ");

        for (int j = 0; j < values.Length; j++)
        {
            get(values[j], cultures);
        }

        Console.WriteLine("\n");
        string s = "123 456, 789";

        Console.WriteLine("format of s is invalid ");

        // converting string to specified float
        float val = Convert.ToSingle(s, cultures);

        // display the converted float value
        Console.Write(" {0}, ", val);
    }

    catch (FormatException e)
    {
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }

    catch (OverflowException e)
    {
        Console.Write("Exception Thrown: ");
        Console.Write("{0}", e.GetType(), e.Message);
    }
}

// Defining get() method
public static void get(string s,
           CultureInfo cultures)
{

    // converting string to
    // specified float value
    float val = Convert.ToSingle(s, cultures);

    // display the converted
    // float value
    Console.Write(" {0}, ", val);
}
}

Output:

Converted float value of specified strings:  12.345,  1234.5,  -123.45, 

format of s is invalid 
Exception Thrown: System.FormatException

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.convert.tosingle?view=netframework-4.7.2#System_Convert_ToSingle_System_String_System_IFormatProvider_