krsort

说明

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

对数组按照键名逆向排序，保留键名到数据的关联。主要用于结合数组。

如果成功则返回 TRUE，失败则返回 FALSE。

例子 1. krsort() 例子
<?php $fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); krsort($fruits); foreach ($fruits as $key => $val) { echo "$key = $val\n"; } ?>
上例将输出：
d = lemon c = apple b = banana a = orange

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

参见 asort()，arsort()，ksort()，sort()，natsort() 和 rsort()。

add a note User Contributed Notes

08-Aug-2005 09:37


To create a natural reverse sorting by keys, use the following function:



<?php

function natkrsort($array) 

{

    $keys = array_keys($array);

    natsort($keys);



    foreach ($keys as $k)

    {

        $new_array[$k] = $array[$k];

    }

   

    $new_array = array_reverse($new_array, true);



    return $new_array;

}

?>

peter at pmkmedia dot com
08-Nov-2003 05:51


Best deal sorting:



This is a function that will sort an array with integer keys (weight) and float values (cost) and delete 'bad deals' - entries that are more costly than other entries that have greater or equal weight.



Input: an array of unsorted weight/cost pairs

Output: none



function BEST_DEALS($myarray)

{   // most weight for least cost:

    //  Peter Kionga-Kamau, http://www.pmkmedia.com

    // thanks to Nafeh for the reversal trick

    // free for unrestricted use.

    krsort($myarray, SORT_NUMERIC);

    while(list($weight, $cost) = each($myarray))

    {   // delete bad deals, retain best deals:

        if(!$lastweight)

        {

            $lastweight=$weight;

            $lastcost = $cost;

        }

        else if($cost >= $lastcost) unset($myarray[$weight]);

        else

        {

            $lastweight=$weight;

            $lastcost = $cost;

        }

    }

    ksort($myarray);

}

lolo at phpheaven dot net
29-Nov-2000 04:33


If you want to emulate the krsort function for an older version of php, you can use this piece of code:





function KeyComp($a, $b)


{   


  return -(strcmp($a,$b));


}





function krsort($MyArray)


{


  uksort($MyArray, "KeyComp");


}





Maybe obvious and useless, but who knows...

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