C# Math.pow( ) return Infinity?

Question

i have problems with Math.pow in c# return infinity for example :

  double a=65;
  double b=331;
  Console.Write(Math.Pow(a,b));
  //but return infinty 

but calculator for my pc not return 65 ^ 331 infinity there are real number return this :1.1866456424809823888425970808655e+600

i use cast to (long) but the result not same windows calculator please i need the variable type is return same window calculator

Answer 1

double has a limited range; it cannot store this number.

Use BigInteger.

Answer 2

Math.pow has a limited range it can function with. See the MSDN docs for more details.

I'm not sure why you're trying to calculate 65^331. One work-around would be to use the BigInteger class:

BigInteger result = new BigInteger(Math.pow(65, 331))

If that doesn't work, there's always good ol' fashioned multiplication:

BigInteger product = 1;
BigInteger a = 65;

for (int i = 0; i < 331; i++) {
    product = BigInteger.Multiply(product, a);
}

This should return the value you want.