On 16/05/07, Brian Moon <[EMAIL PROTECTED]> wrote:
Michael Wallner wrote:
> [EMAIL PROTECTED] wrote:
>> ID: 41401
>> Updated by: [EMAIL PROTECTED]
>> Reported By: drlippman at yahoo dot com
>> -Status: Open
>> +Status: Bogus
>> Bug Type: Math related
>> Operating System: Windows, Linux
>> PHP Version: 4.4.7
>> New Comment:
>>
>> [2007-05-15 15:44:07] drlippman at yahoo dot com
>>
>> Description:
>> ------------
>> Left-to-right order of operations does not appear to be honored when
>> dividing by a negative
>>
>> Reproduce code:
>> ---------------
>> 1/-2*5
>>
>> Expected result:
>> ----------------
>> -2.5
>>
>> Actual result:
>> --------------
>> -.1
>
> Should all these three examples give the same result?
>
> $ php -r 'var_dump(-1/2*5, 1/-2*5, 1/2*-5);'
> float(-2.5)
> float(-0.1)
> float(-2.5)
According to my memory of Please My Dear Aunt Sally these should be:
-1/2*5 = -.1
1/-2*5 = -.1
1/2*-5 = -.1
So, that is bad if PHP answers that way. Someone please correct me if
my memory is wrong. Is there some rule that negative values should be
done first before positive values?
I'm in the UK and I was taught (over 35 years ago at least) about BODMAS
Brackets Orders Division Multiplication Addition Subtraction.
http://en.wikipedia.org/wiki/BODMAS
--
Brian Moon
Senior Developer
------------------------------
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It's good to be cheap =)
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Richard Quadling
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