php array_map array_multisort Efficiently handle multi-dimensional array sorting_PHP tutorial

To sort multi-dimensional arrays, the general approach is
1. Get the sorted data and put it into the array $arrSort. The key index is the index of the array to be sorted, ensuring uniqueness
2. Use the sorting function sort, etc. $arrSort is sorted.
3 Traverse $arrSort, obtain the data of the multi-dimensional array according to its index, and reconstruct the sorted multi-dimensional array.

Copy code The code is as follows:

Array
(
[0] => Array
(
[link] => test
[name] => ; test.rpm
[type] => file
[size] => 988.9k
[mtime] => 1185160178)
....
)

I found a sorting function on the Internet a long time ago. It is not efficient, but it is very practical

Copy the code The code is as follows:

_array_sort($arrFile, 1, 1);//Sort according to the name field
_array_sort($arrFile, 3, 1);//Sort according to the size field
/*
@records Array to be sorted
@field Field to be sorted, pay attention to whether it is a number
@reverse forward or reverse order
*/
function _array_sort($records, $field, $reverse, $ defaultSortField = 0)
{
$uniqueSortId = 0;
$hash = array();
$sortedRecords = array();
$tempArr = array();
$ indexedArray = array();
$recordArray = array();

foreach($records as $record)
{
$uniqueSortId++;
$recordStr = implode("| ", $record)."|".$uniqueSortId;
$recordArray[] = explode("|", $recordStr);
}

$primarySortIndex = count($record);
$records = $recordArray;

foreach($records as $record)
{
$hash[$record[$primarySortIndex]] = $record[$field];
}
uasort($hash, "strnatcasecmp");
if($reverse)
$hash = array_reverse($hash, true);

$valueCount = array_count_values($hash );

foreach($hash as $primaryKey => $value)
{
$indexedArray[] = $primaryKey;
}

$i = 0 ;
foreach($hash as $primaryKey => $value)
{
$i++;
if($valueCount[$value] > 1)
{
foreach ($records as $record)
{
if($primaryKey == $record[$primarySortIndex])
{
$tempArr[$record[$defaultSortField]."__".$i ] = $record;
break;
}
}

$index = array_search($primaryKey, $indexedArray);

if(($i == count ($records)) || ($value != $hash[$indexedArray[$index+1]]))
{
uksort($tempArr, "strnatcasecmp");

if ($reverse)
$tempArr = array_reverse($tempArr);

foreach($tempArr as $newRecs)
{
$sortedRecords [] = $newRecs;
}

$tempArr = array();
}
}
else
{
foreach($records as $record)
{
if($primaryKey == $record[$primarySortIndex])
{
$sortedRecords[] = $record;
break;
}
}
}
}
return $ sortedRecords;
}

II Use array_map and array_mutisor to sort
array_mutisor can also perform secondary or triple sorting based on multiple values, which is incomparable to the previous function.

Copy code The code is as follows:

Use array_map to get the array to be sorted
$arrField = array_map(create_function( '$n', 'return $n["size"];'), $arrFile);
//Use array_mutisor to sort
$array_multisort($arrField, SORT_DESC, $arrFile);

III Final test
Test with an array of 188 data, sort 50 times to find the average.
The first way
0.04269016 name
0.04267142 size
The second way Method
0.001249 name
0.00083924 size

The result is self-evident

http://www.bkjia.com/PHPjc/320223.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/320223.htmlTechArticleTo sort multi-dimensional arrays, the general approach is 1. Get the sorted data and put it into the array $arrSort. The key index is the index of the array to be sorted, ensuring uniqueness 2. Use the sorting function...