Error adding double values

Question

Processing in my application requires adding huge double values,
for instance i am adding 36561584400629760 and 1152062986011661
and instead of getting 37713647386641421 I get 37713647386641424.
Does somebody have a clue as to what the problem could be?
I tried using BigInteger and primitive double datatypes.
Thanks

Answer 1

doubles precision is about 16 digits. Try this     BigDecimal bd1 = new BigDecimal("36561584400629760"),
              bd2 = new BigDecimal("1152062986011661");
     System.out.println(bd1.add(bd2));
or
     BigInteger bi1 = new BigInteger("36561584400629760"),
              bi2 = new BigInteger("1152062986011661");
     System.out.println(bi1.add(bi2));