Java two's complement binary to integer

java binary twos-complement
omegaFlame picture omegaFlame · Apr 5, 2013 · Viewed 24.2k times · Source

I know that converting a decimal to binary with Integer.toBinaryString(355) = 0000000101100011 and Integer.toBinaryString(-355) = 1111111010011101 (where I take the lower 16 bits of the 32 bit result).

What I would like to do is the other way and take a 16-bit twos's complement binary string and to convert to decimal.

i.e.

0000000000110010 =  50
1111111111001110 = -50

Rather than 1111111111001110 = 65486

How would I do this?

Answer

Sergey Kalinichenko picture Sergey Kalinichenko · Apr 5, 2013

You need to read the result into short.

short res = (short)Integer.parseInt("1111111111001110", 2);
System.out.println(res);

This prints -50.

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