4 Jul
2016
4 Jul
'16
4:43 a.m.
On 7/1/2016 11:57 PM, Mark Brown wrote:
On Thu, Jun 30, 2016 at 03:51:51PM +0800, John Hsu wrote:
Yes, it'll be more readable. I have a question. Why to add !! in front of bit wise operation? What does it mean?
It's redundant in almost all cases. It translates an integer value into a 0/1 value (so if you've got a value of 2 it'll end up as 1) by doing a double not. This very rarely matters unless you're storing the value in an integer and comparing it to 1 to check for truth, otherwise C will translate any non-zero value into true in any logic context.
Thank you for the explanation. I get the purpose now and will change the expression of function for clear intent.