What is ~~ in JavaScript?

Question

I was just messing with random stuff, while I found something interesting..

if I have ~ before a number, for example I have tried

~110100100 // result will be  " -110100101 "
~11 // result will be " -12 "

is it making it negative and reducing it by 1? I don't have any idea, can anyone pleas explain this??

ones complement https://en.wikipedia.org/wiki/Ones'_complement — Jaromanda X, Sep 16 '15 at 12:00

score 43 · Accepted Answer · edited Sep 21 '18 at 10:59

43

The operator ~ returns that result:

~N = -(N+1)

But this is an effect of inverting the value of all bits of a variable.

Double tilde ~~ is used to convert some types to int, since ~ operator converts the value to a 32-bit int before inverting its bits. Thus:

~~'-1' = -1
~~true = 1
~~false = 0
~~5.6 = 5

edited Sep 21 '18 at 10:59

Abdullah Khan

answered Sep 16 '15 at 12:03

Joanvo

1

Oh thanks! i've never seen this used widely before so i got confused – Adarsh Hegde Sep 16 '15 at 14:18
1

Nice. Short but to the point! – Llama D'Attore Jul 06 '20 at 08:59

1 Answers1