javascript按位运算符问题

Question

当我这样做时在 Javascript 中

var num = 1;

~ num == -2

为什么 ~num 不等于 0

in binary 1 is stored as 1 ... thus not 1 should be 0

or it is stored like 0001 thus not 0001 would be 1110

I think I am missing something... can someone clear this up

Answer 1

查找Two's complement对于带符号的二进制数

让我们假设一个 javascript 数字是 8 位宽(实际上不是):

然后

1 = 0000 0001b

和

~1 = 1111 1110b

-2的二进制表示是什么

0000 0010b =  2
0000 0001b =  1
0000 0000b =  0
1111 1111b = -1
1111 1110b = -2