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Message-ID: <20840717.cCmZMDQWIF@PointedEars.de>
From: Thomas 'PointedEars' Lahn <PointedEars@web.de>
Reply-To: Thomas 'PointedEars' Lahn <php@PointedEars.de>
Organization: PointedEars Software (PES)
Date: Tue, 03 Apr 2012 15:52:47 +0200
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Subject: Re: A little tip
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Shelly wrote:

> On 3/30/2012 4:30 PM, Thomas Mlynarczyk wrote:
>> Shelly schrieb:
>>> $val = TRUE;
>>
>>> $val &= TRUE;
>>>
>>> which is identical to
>>>
>>> $val = $val && TRUE;
>>
>> No. &= is a bitwise operator while && means the logical AND operator. So
>> when you do $val &= TRUE, PHP is trying to do TRUE & TRUE, but since
>> bitwise operators only work with integers, TRUE is first coerced into
>> the integer 1. So the operation ends up as 1 & 1 yielding the integer 1.
>> Thus, $val = 1. The === operator checks the type of the operands which
>> are int and bool and thus not the same, while == tries to convert the
>> operands into something "comparable" and since they are both "truish"
>> the result is TRUE here.
> 
> Thank you.  That makes a lot of sense.  So, what I have to do if I want
> to use === is to use the expanded form
> 
> $val = $val && TRUE;

You keep missing the point.  That is _not_ "the expanded form" of anything.  
`&=' and `&&' are *different* operators; the first one is a *bitwise* 
operator, the second is a *logical* (boolean) one.

In that sense,

  x = x & 1;

is "the expanded form" of

  x &= 1;

<http://php.net/operators>

Please do not full-quote.


PointedEars
-- 
> If you get a bunch of authors […] that state the same "best practices"
> in any programming language, then you can bet who is wrong or right...
Not with javascript. Nonsense propagates like wildfire in this field.
  -- Richard Cornford, comp.lang.javascript, 2011-11-14