ksort

说明

bool ksort ( array &array [, int sort_flags] )

对数组按照键名排序，保留键名到数据的关联。本函数主要用于关联数组。

如果成功则返回 TRUE，失败则返回 FALSE。

例 1. ksort() 例子


<?php
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
ksort($fruits);
foreach ($fruits as $key => $val) {
    echo "$key = $val\n";
}
?>

上例将输出：

a = orange
b = banana
c = apple
d = lemon

可以用可选参数 sort_flags 改变排序的行为，详情见 sort()。

参见 asort()，arsort()，krsort()，uksort()，sort()，natsort() 和 rsort()。

注意: 第二个参数是 PHP 4 新加的。

add a note User Contributed Notes

don dot hosek at gmail dot com
25-May-2007 01:37


It's worth noting that ksort is also handy if you want to be able to do manipulations on an numerically-keyed array which may not have been initialized in numerical order: 



$a[2]=7;

$a[0]=1;

$a[1]=6;



foreach($a as $b) {

  echo "$b ";

}



$a = ksort($a);



foreach($a as $b) {

  echo "$b ";

}

06-Nov-2006 01:26


Why not just use built-in PHP functions? You can do an in-place natural sort by keys with:



uksort($array, 'strnatcasecmp');

richard dot quadling at bandvulc dot co dot uk
24-Oct-2005 08:10


Just to complete the comments made by ssb45.



If the supplied array is an empty array, the value returned is NOT an array.



All that is required is to pre-initialize the result.



function natksort(&$aToBeSorted)

    {

    $aResult = array();

    $aKeys = array_keys($aToBeSorted);

    natcasesort($aKeys);

    foreach ($aKeys as $sKey)

        {

        $aResult[$sKey] = $aToBeSorted[$sKey];

        }

    $aToBeSorted = $aResult;

    return True;

    }

ssb45 at cornell dot edu
30-Jun-2005 11:58


The function that justin at booleangate dot org provides works well, but be aware that it is not a drop-in replacement for ksort as is.  While ksort sorts the array by reference and returns a status boolean, natksort returns the sorted array, leaving the original untouched.  Thus, you must use this syntax:



$array = natksort($array);



If you want to use the more natural syntax:



$status = natksort($array);



Then use this modified version:



function natksort(&$array) {

    $keys = array_keys($array);

    natcasesort($keys);



    foreach ($keys as $k) {

        $new_array[$k] = $array[$k];

    }



    $array = $new_array;

    return true;

}

justin at booleangate dot org
18-Jan-2005 09:04


Here's a handy function for natural order sorting on keys.



function natksort($array) {

  // Like ksort but uses natural sort instead

  $keys = array_keys($array);

  natsort($keys);



  foreach ($keys as $k)

    $new_array[$k] = $array[$k];



  return $new_array;

}

yaroukh at email dot cz
06-May-2004 03:08


I believe documentation should mention which of array-functions do reset the internal pointer; this one does so ...

pedromartinez at alquimiapaginas dot com
29-Nov-2003 03:58


A list of directories can be listed sorted by date (newer first) with this script. This is usefull if the directories contain (for example) pictures and you want the newer to appear first.



$maindir = "." ;

$mydir = opendir($maindir) ;



// SORT

$directorios = array();

while (false !== ($fn = readdir($mydir)))

{

    if (is_dir($fn) && $fn != "." && $fn != "..") 

    {

        $directory = getcwd()."/$fn";

        $key = date("Y\-m\-d\-His ", filectime($directory));

        $directorios[$key] = $directory;

    }

}



ksort($directorios);

$cronosdir = array();

$cronosdir = array_reverse($directorios);



while (list($key, $directory) = each($cronosdir)) {

    echo "$key = $directory<bR>";

}



Pedro

09-Mar-2002 03:09


here 2 functions to ksort/uksort an array and all its member arrays



function tksort(&$array)

  {

  ksort($array);

  foreach(array_keys($array) as $k)

    {

    if(gettype($array[$k])=="array")

      {

      tksort($array[$k]);

      }

    }

  }



function utksort(&$array, $function)

  {

  uksort($array, $function);

  foreach(array_keys($array) as $k)

    {

    if(gettype($array[$k])=="array")

      {

      utksort($array[$k], $function);

      }

    }

  }

delvach at mail dot com
06-Nov-2001 09:29


A real quick way to do a case-insensitive sort of an array keyed by strings:





uksort($myArray, "strnatcasecmp");

sbarnum at mac dot com
19-Oct-2001 10:54


ksort on an array with negative integers as keys yields some odd results.  Not sure if this is a bad idea (negative key values) or what.

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