Re: [RFC] Comparison and conversion inconsistency - need more info

From: Date: Sat, 16 Nov 2013 17:16:43 +0000
Subject: Re: [RFC] Comparison and conversion inconsistency - need more info
References: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15  Groups: php.internals 
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On Sat, Nov 16, 2013 at 6:22 AM, Marc Bennewitz <php@marc-bennewitz.de>wrote:

> Hi,
>
> What about the following PHP logic:
> var_dump(null == 0); // TRUE
> var_dump(null < -1); // TRUE
> var_dump(null > -1); // FALSE
>
> How can you explain that ?
>
> Greetings
> Marc
>
>
false ==false // TRUE
false < true // TRUE
false > true // FALSE


It's right here:
http://www.php.net/manual/en/language.operators.comparison.php.
 Halfway
down the page, type of op 1 is null, op 2 is anything.

--
William Bartlett
College of Engineering | Cornell University '14
240-432-5189






> Am 15.11.2013 00:03, schrieb Yasuo Ohgaki:
> > Hi all,
> >
> > On Tue, Nov 12, 2013 at 4:03 AM, Sanford Whiteman <
> > swhitemanlistens-software@cypressintegrated.com> wrote:
> >
> >>> You don't have to think the current documentation is awful to find ways
> >>> of improving it.
> >>
> >> Sure, go for it!
> >
> >
> > I wrote my misunderstanding to my personal blog. It seems many people
> > misunderstand it, just like me :)
> >
> > Any improvement/correction?
> > min() manual page is better to be updated. I'll add min() example blow to
> > min() manual
> > page also.
> >
> > Index: operators.xml
> > ===================================================================
> > --- operators.xml (リビジョン 332115)
> > +++ operators.xml (作業コピー)
> > @@ -1262,7 +1262,7 @@
> >        <row>
> >         <entry><type>bool</type> or
> > <type>null</type></entry>
> >         <entry>anything</entry>
> > -       <entry>Convert to <type>bool</type>, &false; &lt;
> > &true;</entry>
> > +       <entry>Convert to <type>bool</type> both side, &false;
> > &lt;
> > &true;</entry>
> >        </row>
> >        <row>
> >         <entry><type>object</type></entry>
> > @@ -1298,8 +1298,28 @@
> >       </tbody>
> >      </tgroup>
> >     </table>
> > +
> >     <para>
> >      <example>
> > +     <title>Boolean/null comparison</title>
> > +     <programlisting role="php">
> > +<![CDATA[
> > +<?php
> > +// Bool and null are compared as bool always
> > +var_dump(1 == TRUE);  // TRUE - same as (bool)1 == TRUE
> > +var_dump(0 == FALSE); // TRUE - same as (bool)0 == FALSE
> > +var_dump(100 < TRUE); // FALSE - same as (bool)100 < TRUE
> > +var_dump(-10 < FALSE);// FALSE - same as (bool)-10 < FALSE
> > +var_dunp(min(-100,-10, NULL, 10, 100); // NULL - (bool)NULL < (bool)-100
> > is FALSE < TRUE
> > +?>
> > +]]>
> > +     </programlisting>
> > +    </example>
> > +   </para>
> > +
> > +
> > +   <para>
> > +    <example>
> >       <title>Transcription of standard array comparison</title>
> >       <programlisting role="php">
> >  <![CDATA[
> >
>
> --
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