Hi All,
This is probably a really basic syntax question, but I can't find the answer.
Can anyone tell me what this expression means?
objPoint.x = -objPoint.x;
As a note, objPoint is a CGPoint
Thanks!
+2
A:
You change the horizontal coordination to its negative.
Another example is that:
x = 7;
x = -x;
Then it will become x = -7;
This is the evaluation process:
The evaluation process will be ran in the right hand side first, so the process is:
replace x with 7, the right hand side of -x will become -7.
then assign it to the left hand side: x = -7;
vodkhang
2010-06-30 02:03:27
thanks, I must be exhausted to not have realized that!
GL777
2010-06-30 02:18:36
Thanks for some editting, but I mean because x = 7 so -x = - (7)
vodkhang
2010-06-30 02:50:07
What does that last statement return? What does `(-7 == (-x = -(7)))` evaluate to? I'm assuming true, since it will do the assignment then evaluate the expression. Also, will `(-x) = (-7)` compile?
Jamie Wong
2010-06-30 03:13:52
No, I mean for the expression x = -x, first, the computer will replace x by 7 so the right hand side will become -7. That's what it means for -x = -7
vodkhang
2010-06-30 03:20:42