C Macro equivalent in Javascript [duplicate]

Question

The following macro is to determine if two numbers have the same sign, is for 2's complement number representation.

#define SAME_SIGNS( a, b )  (((long) ((unsigned long) a ^ (unsigned long) b)) >= 0 )

Can anyone suggest a javascript equivalent function?

In other words -- Could someone please translate that macro in javascript function? — user2533495
– user2533495, Commented Jun 28, 2013 at 22:28
literal translate: function sameSigns(a, b) { return (((a >>> 0) ^ (b >>> 0)) | 0) >= 0; } // But notice that a, b are FLOAT in NOT INTEGER, so the implementation is wrong somehow. — tsh
– tsh, Commented May 31, 2017 at 5:31

Virus721 · Accepted Answer · 2013-06-28 23:04:47Z

1

(a < 0 === b < 0)

or

(a * b > 0) // If one of a or b is 0, can't tell.

or

(a < 0 && b < 0 || a > 0 && b > 0)

true -> same, else different

answered Jun 28, 2013 at 22:28

Virus721

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2 Comments

Shorter version with no risk of overflow return ((a<0) == (b<0)); (Adapted from Rik's answer)

Nailed it :). I suggest you to update your answer.

amaurea · Accepted Answer · 2013-06-28 22:27:27Z

0

It won't be exactly the same, but how about something like !(a*b<0)?

answered Jun 28, 2013 at 22:27

amaurea

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