Why negation of 20 is equal to -21 (~20 = -21)?

Question

Can any body please explain me why negation of 20 is equals to -21?

Answer 1

The tilde (~) is the bitwise NOT operator, not a negator. For that, just use a negative sign (-).

The bitwise NOT operator it stated to "find the complement of an integer" by inverting the bits of a number. That is, converting it to binary and swapping all the 1's and 0's. Read more here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_NOT (although written for javascript specifically, the same concepts here work across many languages)

Answer 2

https://www.sololearn.com/learn/4076/?ref=app

or ~(a)= -(a+1)

for ex 00000000 11111111
first four ones reprsent negative sign and remain represent 1 in binary format

Answer 3

Thank you.