Decimal.ToInt64() Method in C#

This method is used to convert the value of the specified Decimal to the equivalent 64-bit signed integer. A user can also convert a Decimal value to a 64-bit integer by using the Explicit assignment operator.

Syntax: public static long ToInt64 (decimal d);

Here, the value is the decimal number which is to be converted.

Return Value: It returns a 64-bit signed integer equivalent to the specified value.

Exception: This method will give OverflowException if the specified value is less than MinValue or greater than MaxValue.

Below programs illustrate the use of the above-discussed method:

Example 1:

// C# program to demonstrate the
// Decimal.ToInt64(Decimal) Method
using System;

class GFG {

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

            // Taking decimal variables
            Decimal dec1 = -926534668654775808.859m;
            Decimal dec2 = 4897498545.2364654M;

            // using Decimal.ToInt64(Decimal) Method
            // Here long means Int64
            long val1 = Decimal.ToInt64(dec1);

            // using Decimal.ToInt64(Decimal) Method
            // Here long means Int64
            long val2 = Decimal.ToInt64(dec2);


            // Printing the Int64 value
            Console.WriteLine("The Int64 value "
                            + "is : {0}", val1);

            // Printing the Int64 value
            Console.WriteLine("The Int64 value "
                            + "is : {0}", val2);

        }

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

Output:

The Int64 value is : -926534668654775808
The Int64 value is : 4897498545

Example 2: For OverflowException

// C# program to demonstrate the
// Decimal.ToInt64(Decimal) Method
using System;

class GFG {

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

            // Taking decimal variables
            Decimal dec1 = Decimal.MinValue;

            // Taking the maximum value
            // of Decimal
            Decimal dec2 = Decimal.MaxValue;

            // using Decimal.ToInt64(Decimal) Method
            // Here long means Int64
            // It will give error
            long val1 = Decimal.ToInt64(dec1);

            // using Decimal.ToInt64(Decimal) Method
            // Here long means Int64
            // It will give error
            long val2 = Decimal.ToInt64(dec2);


            // Printing the Int64 value
            Console.WriteLine("The Int64 value "
                            + "is : {0}", val1);

            // Printing the Int64 value
            Console.WriteLine("The Int64 value "
                            + "is : {0}", val2);

        }

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

Output:

Exception Thrown: System.OverflowException

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.decimal.toint64?view=netframework-4.7.2