How do I add two strings in C#?

Question

I have a method that will take two strings and return the sum of them in string format.

I use string because there will be +-30 digit numbers. I’m having trouble converting to add. :/

Answer 1

How do you talk about converting to ulong I’ll assume that the strings represent whole.

public string Somar(string numA, string numB)
{
    BigInteger bigA = BigInteger.Parse(numA);
    BigInteger bigB = BigInteger.Parse(numB);
    return BigInteger.Add(bigA, bigB).ToString();
}

If you want to treat float or double change Biginteger for Bigdecimal. An exception of the kind Formatexception will be launched if it is not possible to do the Parse.

Answer 2

If you are using . Net Framework 4.0 or higher you can use Biginteger. You only need to reference the following Assembly System.Numerics.