A cleaner (I think) way to sort a list of files into reversed order based on their modification date.
<?php
$path = $_SERVER[DOCUMENT_ROOT]."/files/";
$dh = @opendir($path);
while (false !== ($file=readdir($dh)))
{
if (substr($file,0,1)!=".")
$files[]=array(filemtime($path.$file),$file); #2-D array
}
closedir($dh);
if ($files)
{
rsort($files); #sorts by filemtime
#done! Show the files sorted by modification date
foreach ($files as $file)
echo "$file[0] $file[1]<br>\n"; #file[0]=Unix timestamp; file[1]=filename
}
?>rsort
(PHP 4, PHP 5, PHP 7, PHP 8)
rsort — Sort an array in descending order
Description
Sorts array in place by values
in descending order.
Note: If two members compare as equal, they retain their original order. Prior to PHP 8.0.0, their relative order in the sorted array was undefined.
Note: This function assigns new keys to the elements in
array. It will remove any existing keys that may have been assigned, rather than just reordering the keys.
Note: Resets array's internal pointer to the first element.
Parameters
array-
The input array.
flags-
The optional second parameter
flagsmay be used to modify the sorting behavior using these values:Sorting type flags:
-
SORT_REGULAR- compare items normally; the details are described in the comparison operators section -
SORT_NUMERIC- compare items numerically -
SORT_STRING- compare items as strings -
SORT_LOCALE_STRING- compare items as strings, based on the current locale. It uses the locale, which can be changed using setlocale() -
SORT_NATURAL- compare items as strings using "natural ordering" like natsort() -
SORT_FLAG_CASE- can be combined (bitwise OR) withSORT_STRINGorSORT_NATURALto sort strings case-insensitively
-
Return Values
Always returns true.
Examples
Example #1 rsort() example
<?php
$fruits = array("lemon", "orange", "banana", "apple");
rsort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>The above example will output:
0 = orange 1 = lemon 2 = banana 3 = apple
The fruits have been sorted in reverse alphabetical order.
See Also
- sort() - Sort an array in ascending order
- arsort() - Sort an array in descending order and maintain index association
- krsort() - Sort an array by key in descending order
- The comparison of array sorting functions
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User Contributed Notes 2 notes
Alex M ¶
21 years ago
ray at non-aol dot com ¶
21 years ago
Like sort(), rsort() assigns new keys for the elements in array. It will remove any existing keys you may have assigned, rather than just reordering the keys. This means that it will destroy associative keys.
$animals = array("dog"=>"large", "cat"=>"medium", "mouse"=>"small");
print_r($animals);
//Array ( [dog] => large [cat] => medium [mouse] => small )
rsort($animals);
print_r($animals);
//Array ( [0] => small [1] => medium [2] => large )
Use KSORT() or KRSORT() to preserve associative keys.