1.NounThe number obtained by complementing every bit of a given number and adding one. A number and its complement add to 2, where n is the word size of the machine.
"The two's complement of 0xAAAA is 0x5556 on a 16-bit machine, and 0xFFFF5556 on a 32-bit machine."
2.NounThe convention by which bit patterns with high bit 0 represent positive numbers from 0 to
2
n
−
1
−
1
{\displaystyle 2^{n-1}-1}
directly, while bit patterns with high bit 1 represent negative numbers from −1 to
−
2
n
−
1
{\displaystyle -2^{n-1}}
, n being the word size of the machine, and the numeric complement of a number is its two's complement.
"Nearly all modern computers use two's complement for integer arithmetic."