BigInteger

For large values, the double and decimal types are not easy to use. The developer always worries about overflow problems. A better type is needed for big integers.

With the BigInteger type, we have a special type in .NET that we can use to handle big numbers. We must add a reference to the System.Numerics assembly first.

Example

Let us begin with this example. It does nothing special, but it adds together 2 values with the maximum value of double. Our BigInteger is a "doubled" double.

using System;
using System.Numerics;

// Create 2 BigIntegers from the maximum value of a double.
BigInteger big1 = new BigInteger(double.MaxValue);
BigInteger big2 = new BigInteger(double.MaxValue);

// Add the 2 values together.
BigInteger double1 = BigInteger.Add(big1, big2);

// Print the values of the BigIntegers.
Console.WriteLine("DOUBLE MAX: " + big1.ToString());
Console.WriteLine("DOUBLE MAX * 2: " + double1.ToString());
DOUBLE MAX: 179...(omitted)...368
DOUBLE MAX * 2: 359...(omitted)...736

Notes, BigInteger

This is just a sampling of the power of BigInteger. Usually programs that need BigInteger will use Multiply, as multiplication tends to yield much larger values than Add.

Even if you are not focused on numerics, knowing that BigInteger exists and it can be used to store large integers is useful.