2’s complement hex number to decimal in java

This seems to trick java into converting the number without forcing a positive result:

Integer.valueOf("FFFF",16).shortValue(); // evaluates to -1 (short)

Of course this sort of thing only works for 8, 16, 32, and 64-bit 2’s complement:

Short.valueOf("FF",16).byteValue(); // -1 (byte)
Integer.valueOf("FFFF",16).shortValue(); // -1 (short)
Long.valueOf("FFFFFFFF",16).intValue(); // -1 (int)
new BigInteger("FFFFFFFFFFFFFFFF",16).longValue(); // -1 (long)

Example here.

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