How to use PHP array sorting function_PHP tutorial

There are many data sorting functions in PHP, including one-dimensional array sorting functions and two-dimensional array sorting functions, including simple sort function ascending sorting, rsort descending order, etc.

PHP array sorting functions include

sort ( &$arr [,fruits] ) Sort the array from low to high and assign a new key name. Return bool
rsort ( &$arr [,fruits] ) Reverse sort the array and assign new key names
asort ( &$arr [,fruits] ) sorts the array, keeping the index unchanged
arsort( &$arr [,fruits] ) sorts the array in reverse order and keeps the index unchanged

ksort ( &$arr [,fruits] ) sorts the array by key name
krsort( &$arr [,fruits] ) sorts the group numbers in reverse order by key name

natsort( &$arr ) Performs ‘natural sorting’ on array key values, sorting by length, alphabet, etc.
natcasesort( &$arr ) performs case-insensitive ‘natural ranking’ of arrays

usort ( &$arr , cmp_function ) User-defined function sorts an array and rearranges key names
uksort (&$arr, cmp_function) User-defined function sorts an array by key name
uasort (&$arr, cmp_function) user-defined function sorts the array and keeps the index unchanged

array_multisort( $arr , mixed)

The second parameter can change the sorting behavior based on the value

SORT_REGULAR Normal comparison unit SORT_NUMERIC unit is compared as a number
SORT_STRING cells are compared as strings SROT_LOCALE_STRING cells are compared as strings according to the current local settings

--------------------sort function ascending order----------------------------- ------
bool sort ( array &$array [, int $sort_flags= SORT_REGULAR ] )

The code is as follows

Copy code

代码如下	复制代码
$fruits = array("lemon", "orange", "banana", "apple"); sort($fruits); var_dump($fruits); ?> 结果： array 0 => string  'apple' (length=5)   1 => string  'banana' (length=6)   2 => string  'lemon' (length=5)   3 => string  'orange' (length=6)

$fruits = array("lemon", "orange", "banana", "apple"); sort($fruits);

代码如下	复制代码
$fruits = array("lemon", "orange", "banana", "apple"); rsort($fruits); var_dump($fruits); ?> 结果： array   0 => string  'orange' (length=6)   1 => string  'lemon' (length=5)   2 => string  'banana' (length=6)   3 => string  'apple' (length=5)

var_dump($fruits); ?> Result: array 0 => string 'apple' (length=5) 1 => string 'banana' (length=6) 2 => string 'lemon' (length=5) 3 => string 'orange' (length=6)

--------------------rsort in descending order--------------------

The code is as follows	Copy code
$fruits = array("lemon", "orange", "banana", "apple"); rsort($fruits); var_dump($fruits); ?> Result: array 0 => string 'orange' (length=6) 1 => string 'lemon' (length=5) 2 => string 'banana' (length=6) 3 => string 'apple' (length=5)

---------------asort is arranged in ascending order of the two-dimensional array values ​​(maintaining the association of key=>value)----------

The code is as follows

Copy code

代码如下	复制代码
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); asort($fruits); var_dump($fruits); ?> 结果： array   'c' => string  'apple' (length=5)   'b' => string  'banana' (length=6)   'd' => string  'lemon' (length=5)   'a' => string  'orange' (length=6)

$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
asort($fruits);
var_dump($fruits);
?>
Result:
array
'c' =>

string

代码如下	复制代码
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); arsort($fruits); var_dump($fruits); ?> 结果 array   'a' => string  'orange' (length=6)   'd' => string  'lemon' (length=5)   'b' => string  'banana' (length=6)   'c' => string  'apple' (length=5)

'apple' (length=5)
'b' =>

代码如下	复制代码
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); ksort($fruits); var_dump($fruits); ?> 结果 array 'a' => string  'orange' (length=6)   'b' => string  'banana' (length=6)   'c' => string  'apple' (length=5)   'd' => string  'lemon' (length=5)

string

'banana' (length=6)
'd' =>

代码如下	复制代码
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); krsort($fruits); var_dump($fruits); ?> array   'd' => string  'lemon' (length=5)   'c' => string  'apple' (length=5)   'b' => string  'banana' (length=6)   'a' => string  'orange' (length=6)

string 'lemon' (length=5)
'a' => string 'orange' (length=6)

--------------arsort is arranged in descending order of the two-dimensional array values ​​(maintaining the association of key=>value)------------- -

The code is as follows	Copy code
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); arsort($fruits); var_dump($fruits); ?> Results array 'a' => string 'orange' (length=6) 'd' => string 'lemon' (length=5) 'b' => string 'banana' (length=6) 'c' => string 'apple' (length=5)

--------------------ksort sorts the array in ascending order of keys----------------

The code is as follows	Copy code
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); ksort($fruits); var_dump($fruits); ?> Results array 'a' => string 'orange' (length=6) 'b' => string 'banana' (length=6) 'c' => string 'apple' (length=5) 'd' => string 'lemon' (length=5)

---------------------krsort sorts the array keys in descending order------------------ -------------

The code is as follows	Copy code
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); krsort($fruits); var_dump($fruits); ?> array 'd' => string 'lemon' (length=5) 'c' => string 'apple' (length=5) 'b' => string 'banana' (length=6) 'a' => string 'orange' (length=6)

----------------usort function sorts according to user-defined functions----------------

The code is as follows

Copy code

代码如下	复制代码
function cmp($a, $b) {     if ($a == $b) {         return 0;     }     return ($a } $a = array(3, 2, 5, 6, 1); usort($a, "cmp"); var_dump($a); ?> 结果： array   0 => int  1   1 => int  2   2 => int  3   3 => int  5   4 => int  6

function cmp($a, $b)
{
If ($a == $b) {
         return 0;
}
Return ($a }

$a = array(3, 2, 5, 6, 1);

代码如下	复制代码
function cmp($a, $b) {     $a = preg_replace('@^(a|an|the) @', '', $a);     $b = preg_replace('@^(a|an|the) @', '', $b);     return strcasecmp($a, $b); } $a = array("John" => 1, "the Earth" => 2, "an apple" => 3, "a banana" => 4); uksort($a, "cmp"); var_dump($a); ?> 结果： array   'an apple' => int  3   'a banana' => int  4   'the Earth' => int  2   'John' => int  1

usort($a, "cmp");

代码如下

复制代码

// Comparison function function cmp($a, $b) {     if ($a == $b) {         return 0;     }     return ($a } // Array to be sorted $array = array('a' => 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4); var_dump($array); // Sort and print the resulting array uasort($array, 'cmp'); var_dump($array); ?> 结果： array   'a' => int  4   'b' => int  8   'c' => int  -1   'd' => int  -9   'e' => int  2   'f' => int  5   'g' => int  3   'h' => int  -4 array   'd' => int  -9   'h' => int  -4   'c' => int  -1   'e' => int  2   'g' => int  3   'a' => int  4   'f' => int  5   'b' => int  8

var_dump($a);
?>
Result:
array
0 => int 1
1 => int 2
2 => int 3
3 => int 5
4 => int 6

-----------------uksort uses a custom function to sort the array by key-----------------

The code is as follows	Copy code
function cmp($a, $b) { $a = preg_replace('@^(a|an|the) @', '', $a); $b = preg_replace('@^(a|an|the) @', '', $b); Return strcasecmp($a, $b); } $a = array("John" => 1, "the Earth" => 2, "an apple" => 3, "a banana" => 4); uksort($a, "cmp"); var_dump($a); ?> Result: array 'an apple' => int 3 'a banana' => int 4 'the Earth' => int 2 'John' => int 1

------------------uasort uses a custom function to sort the array by value, keeping the index relationship unchanged---------

The code is as follows

Copy code

// Comparison function function cmp($a, $b) { If ($a == $b) {           return 0; } Return ($a } // Array to be sorted $array = array('a' => 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4); var_dump($array); // Sort and print the resulting array uasort($array, 'cmp'); var_dump($array); ?> Result: array 'a' => int 4 'b' => int 8 'c' => int -1 'd' => int -9 'e' => int 2 'f' => int 5 'g' => int 3 'h' => int -4 array 'd' => int -9 'h' => int -4 'c' => int -1 'e' => int 2 'g' => int 3 'a' => int 4 'f' => int 5 'b' => int 8

------------------array_multisort Sort multiple arrays or multidimensional arrays---------

0 =>

The code is as follows

代码如下

复制代码

$ar = array(        array("10", 11, 100, 100, "a"),        array(   1,  2, "2",   3,   1)       );    array_multisort($ar[0], SORT_ASC, SORT_STRING,                 $ar[1], SORT_NUMERIC, SORT_DESC); var_dump($ar); ?> 结果： array   0 =>     array       0 => string  '10' (length=2)       1 => int  100       2 => int  100       3 => int  11       4 => string  'a' (length=1)   1 =>     array       0 => int  1       1 => int  3       2 => string  '2' (length=1)       3 => int  2       4 => int 1

Copy code

$ar = array(
array("10", 11, 100, 100, "a"), array( 1, 2, "2", 3, 1)

);
array_multisort($ar[0], SORT_ASC, SORT_STRING,                      $ar[1], SORT_NUMERIC, SORT_DESC);

var_dump($ar);

?>

Result:

array

0 =>

代码如下	复制代码
function array_sort($arr,$keys,$type='asc'){  $keysvalue = $new_array = array();  foreach ($arr as $k=>$v){   $keysvalue[$k] = $v[$keys];  }  if($type == 'asc'){   asort($keysvalue);  }else{   arsort($keysvalue);  }  reset($keysvalue);  foreach ($keysvalue as $k=>$v){   $new_array[$k] = $arr[$k];  }  return $new_array; }

array

string

'10' (length=2)

1 => int 100 2 => int 100 3 => int

11 4 =>

string 'a' (length=1) 1 => array 0 => int 1 1 => int 3 2 => string '2' (length=1) 3 => int 2 4 => int 1 //Description: 1 In the above example: the $ar array is first arranged in ascending order according to the string value of $ar[0]. If the string values ​​​​are equal, it is then arranged in descending order according to the numeric value of the $ar[1] array. 2. If the parameter at any position of the array_multisort function is an array, it indicates the value used for sorting, If there are multiple array parameters, the previous array value will be sorted first. If it is a constant, such as SORT_ASC, SORT_DESC, SORT_REGULAR,SORT_NUMERIC, SORT_STRING. PHP two-dimensional array sorting function You can use sort(), asort(), arsort() and other functions to sort PHP one-dimensional arrays, but the sorting of PHP two-dimensional arrays needs to be customized. The following function sorts a given two-dimensional array according to the specified key value. Let’s look at the function definition first:

The code is as follows

Copy code

function array_sort($arr,$keys,$type='asc'){ $keysvalue = $new_array = array(); foreach ($arr as $k=>$v){ $keysvalue[$k] = $v[$keys]; } if($type == 'asc'){ asort($keysvalue); }else{ arsort($keysvalue); } reset($keysvalue); foreach ($keysvalue as $k=>$v){ $new_array[$k] = $arr[$k]; } return $new_array; } http://www.bkjia.com/PHPjc/632806.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/632806.htmlTechArticleThere are many data sorting functions in PHP, including one-dimensional array sorting functions and two-dimensional array sorting functions, including simple sort function ascending order, rsort descending order and other php array sorting functions are...