How does the expression "float | 0" produces an integer?

Question

Please describe how does 5.55 | 0 produces 5 in JavaScript. I want to know what is happening in this bitwise operating. Thanks!

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators#Bitwise_OR — Bergi, Jun 07 '14 at 17:01

score 2 · Answer 1 · answered Jun 07 '14 at 16:58

2

The bitwise operators in Javascript automatically coerce their arguments to 32-bit integer values by dropping the fraction and any high-order bits beyond 32. So

5.55 | 0

is treated like:

5 | 0

answered Jun 07 '14 at 16:58

Barmar

741,623
53
500
612

score 1 · Accepted Answer · answered Jun 07 '14 at 16:59

1

The operands of bitwise operations are always converted to signed 32-bit integers in big-endian order and in two's complement format.

That would be

    00000000000000000000000000000101
or  00000000000000000000000000000000
------------------------------------ 
    00000000000000000000000000000101

answered Jun 07 '14 at 16:59

user2291758

715
8
19

Aren't they actually endian-neutral? – harold Jun 07 '14 at 17:58
Hm true, maybe it makes it easier to understand the shift operations. – user2291758 Jun 08 '14 at 09:08

How does the expression "float | 0" produces an integer?

2 Answers2