Sort the element values of the php array in descending order by rsort () function

Sort the array values. In addition to the various sorting methods taught by the teacher, php will directly give you a function rsort (), which is very simple to use, but only suitable for arrays.

Rsort (array, sorttype)

Parameter description
Array is required. Input array.
Sorttype is optional. Specifies how to arrange the values of an array. Possible values:

SORT_REGULAR-default. Process with their original type (without changing the type ).
SORT_NUMERIC-process the value as a number
SORT_STRING-process the value as a string
SORT_LOCALE_STRING-process the value as a string based on local settings *.
 

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<? Php $ My_array = array ("a" => "Dog", "B" => "Cat", "c" => "Horse "); Rsort ($ my_array ); Print_r ($ my_array ); ?> Output: Array ( [0] => Horse [1] => Dog [2] => Cat )

Other references

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$ Data [] = array ('Volume '=> 67, 'version' => 2 ); $ Data [] = array ('Volume '=> 86, 'version' => 1 ); $ Data [] = array ('Volume '=> 85, 'version' => 6 ); $ Data [] = array ('Volume '=> 98, 'version' => 2 ); $ Data [] = array ('Volume '=> 86, 'version' => 6 ); $ Data [] = array ('Volume '=> 67, 'version' => 7 );

In this example, we will sort volume in descending order and edition in ascending order.

Now we have an array containing rows, but array_multisort () needs an array containing columns. Therefore, we use the following code to obtain and sort columns.

// Retrieve the column list

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Foreach ($ data as $ key => $ row ){ $ Volume [$ key] = $ row ['Volume ']; $ Edition [$ key] = $ row ['version']; }

// Sort data by volume in descending order and edition in ascending order
// Use $ data as the last parameter and sort it by a common key
Array_multisort ($ volume, SORT_DESC, $ edition, SORT_ASC, $ data );
 

The data set is sorted as follows:

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Volume | edition ------- + -------- 98 | 2 86 | 1 86 | 6 85 | 6 67 | 2 67 | 7

In fact, there are still many ways to use in sorting, such as the arsort (), asort (), ksort (), krsort (), natsort (), natcasesort (), rsort (), usort (), array_multisort (), and uksort ().