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.

An 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.

A summary

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