Question

I am experimenting with BigIntegers with random values.

BigInteger bi1 = new BigInteger("365375409332725729550921208179070754913983135742");
BigInteger bi2 = new BigInteger("386718480727050819604290866521372728863001258687");

byte[] bytesBi1 = bi1.toByteArray();
byte[] bytesBi2 = bi2.toByteArray();

The first one is the one which produces a strange value.
The second is ok.

Can someone explain to me what I am doing wrong ?

Edit

Here’re the results:

bytesBi1 = [63, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -2]
bytesBi2 = [67, -67, 14, 113, -94, 16, -120, 82, 84, 95, -127, -124, -90, -33, 29, -102, 90, 125, -86, -65]

Answer 1

BigInteger‘s toByteArray() method returns the two’s complement representation of the number.

The values you’re getting are in fact the correct two’s complement representation of the numbers you put in.