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RobotC 3.50 bug 3

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RobotC 3.50 bug 3

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MHTS

Guru

Joined: Sun Nov 15, 2009 5:46 am
Posts: 1023

RobotC 3.50 bug 3

Here is bug #3:


	Code: task main() { nxtDisplayTextLine(0, "value=%d", 0 - 0 + 1); }

This gave the output:


	Quote: value=-1

Sat Sep 15, 2012 4:45 pm

MHTS

Guru

Joined: Sun Nov 15, 2009 5:46 am
Posts: 1023

Re: RobotC 3.50 bug 3

I am trying to figure out how RobotC comes up with -1 in this scenario. Now that I looked back at bug 2 and 3, I'd bet RobotC is evaluating operators with equal precedence backwards. 0 - 0 + 1 = -1 because it is doing 0 - (0 + 1). But if that's true, I am surprise that it didn't get discovered long ago. In any case I played around with different numbers:


	Code: task main() { nxtDisplayTextLine(0, "n0=%d", 0 - 0 + 1); nxtDisplayTextLine(1, "n1=%d", 0 - 3 + 4); nxtDisplayTextLine(2, "n2=%d", 3 - 4 + 5); nxtDisplayTextLine(3, "n3=%d", 3 * 4 + 5); nxtDisplayTextLine(4, "n4=%d", 3 * 4 / 5); }

And it gave the output:


	Code: n0=-1 n1=-7 n2=-6 n3=17 n4=0

So it looks like it is evaluating it from right to left.

Sat Sep 15, 2012 7:04 pm

Dick Swan

Creator

Joined: Fri Feb 09, 2007 9:21 am
Posts: 613

Re: RobotC 3.50 bug 3

Fixed for next release. ROBOTC should be compliant with C operator precedence.

Mon Sep 17, 2012 2:50 pm

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