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Re: sorting readdir output?

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On Mon, 02 Dec 2013 10:54:49 -0800, Richard Yates wrote:

> On Sun, 1 Dec 2013 11:39:20 -0500, richard <noreply@example.com>
> wrote:
> 
> Isn't "false !==" unnecessary?
> 
>><?php
>>
>>if ($handle = opendir('../audio/1960/')) {
>>    echo "Directory handle: $handle\n";
>>    echo "Entries:\n";
>>
>>    /* This is the correct way to loop over the directory. */
>>    while (false !== ($entry = readdir($handle))) {
>>        echo "$entry\n<br>";
>>    }
>>
>>    closedir($handle);
>>}
>>?>
>>
>>This gives the output in an unsorted list.
>>How can I make it so the array is sorted?
>>
>>http://us1.php.net/readdir

1. Please post replies *BELOW* the points they address, this is usenet, 
we've been reading from down the page for years now and it's the way we'd 
like to continue doing it.

2. Your question could be easily answered by reading the relevant manual 
entry for the function concerned. Possibly much faster than by posting to 
usenet and waiting for a response. Perhaps you should try that next time?

3. Said manual entry ( http://www.php.net/manual/en/function.readdir.php 
) contains:

"Return Values

Returns the entry name on success or FALSE on failure.

Warning

This function may return Boolean FALSE, but may also return a non-Boolean 
value which evaluates to FALSE. Please read the section on Booleans for 
more information. Use the === operator for testing the return value of 
this function."

See: http://www.php.net/manual/en/language.types.boolean.php

Which includes:

"Converting to boolean

To explicitly convert a value to boolean, use the (bool) or (boolean) 
casts. However, in most cases the cast is unnecessary, since a value will 
be automatically converted if an operator, function or control structure 
requires a boolean argument.

See also Type Juggling.

When converting to boolean, the following values are considered FALSE:

    the boolean FALSE itself
    the integer 0 (zero)
    the float 0.0 (zero)
    the empty string, and the string "0"  <----------------------****
    an array with zero elements
    an object with zero member variables (PHP 4 only)
    the special type NULL (including unset variables)
    SimpleXML objects created from empty tags

Every other value is considered TRUE (including any resource)."

So yes, "false !==" is needed, because you can have a valid result which 
would evaluate to false (such as the valid file name "0").

-- 
Denis McMahon, denismfmcmahon@gmail.com

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Thread

sorting readdir output? richard <noreply@example.com> - 2013-12-01 11:39 -0500
  Re: sorting readdir output? Norman Peelman <npeelman@cfl.rr.com> - 2013-12-01 11:56 -0500
    Re: sorting readdir output? richard <noreply@example.com> - 2013-12-01 12:13 -0500
  Re: sorting readdir output? Luuk <luuk@invalid.lan> - 2013-12-01 18:32 +0100
    Re: sorting readdir output? Luuk <luuk@invalid.lan> - 2013-12-01 18:35 +0100
    Re: sorting readdir output? richard <noreply@example.com> - 2013-12-01 13:10 -0500
      Re: sorting readdir output? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2013-12-01 13:19 -0500
  Re: sorting readdir output? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2013-12-01 12:59 -0500
    Re: sorting readdir output? "James Harris" <james.harris.1@gmail.com> - 2013-12-01 18:10 +0000
      Re: sorting readdir output? richard <noreply@example.com> - 2013-12-01 13:19 -0500
  Re: sorting readdir output? Denis McMahon <denismfmcmahon@gmail.com> - 2013-12-01 23:41 +0000
  Re: sorting readdir output? Richard Yates <richard@yatesguitar.com> - 2013-12-02 10:54 -0800
    Re: sorting readdir output? Denis McMahon <denismfmcmahon@gmail.com> - 2013-12-02 20:24 +0000
      Re: sorting readdir output? Richard Yates <richard@yatesguitar.com> - 2013-12-02 13:02 -0800
        Re: sorting readdir output? Christoph Michael Becker <cmbecker69@arcor.de> - 2013-12-02 22:33 +0100
      Re: sorting readdir output? Tim Streater <timstreater@greenbee.net> - 2013-12-02 22:20 +0000
        Re: sorting readdir output? Denis McMahon <denismfmcmahon@gmail.com> - 2013-12-02 23:54 +0000

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