PHP multidimensional array Specifies sample code for multi-field ordering _php instance

This article mainly introduces the PHP multidimensional array to specify a multi-field ordering example code, small series feel very good, and now share to everyone, but also for everyone to do a reference. Let's take a look at it with a little knitting.

Introducing the Array_multisort method

array_multisort-to sort multiple arrays or multidimensional arrays. The instructions in its PHP manual are as follows:

Copy the Code code as follows:

BOOL Array_multisort (array & $arr [, Mixed $arg = Sort_asc [, Mixed $arg = Sort_regular [, mixed $ ...])

Parameters

Arr
An array to sort on.

Arg
Each of the following parameters can be another array or the option parameter for the previous array sort flag: Sort_asc, Sort_desc,sort_regular, Sort_numeric, sort_string.
...
Additional Arg ' s.

To implement a field ordering of a specified multidimensional array first

This requires that the array be sorted based on one of the fields, and the arrays are assumed as follows:

  $array = Array (      0=>array (' id ' =>8, ' name ' = ' Tom '),      1=>array (' id ' =>9, ' name ' = ' Peter '),      2=>array (' id ' =>5, ' name ' = ' Jack ')  );

We want to sort by the ID value of the two-dimensional array, the converted array format is as follows:

  $array = Array (      0=>array (' id ' =>5, ' name ' = ' Jack ')      1=>array (' id ' =>8, ' name ' = ' Tom '),      2=>array (' id ' =>9, ' name ' = ' Peter ')  );

To complete the above conversion, you need to use the Array_multisort function described above, as follows:

  Function Sortarrbyonefield (& $array, $field, $desc = False) {    $FIELDARR = array ();    foreach ($array as $k = + $v) {     $FIELDARR [$k] = $v [$field];    }    $sort = $desc = = False? Sort_asc:sort_desc;    Array_multisort ($FIELDARR, $sort, $array);  }

By storing the $field of the individual arrays of the array to be sorted in an array fieldarr, participate in the ordering in the incoming array_multisort. Where the value of the field array is as follows:

Array (0=>8,1=>9,2=>5)

When Array_multisort is passed in, it is equivalent to sorting the $field one-dimensional array, and then rebuilding the incoming sorted array based on the sorted key.

To implement specifying multiple field ordering for a multidimensional array

The above example explains how to implement a multidimensional array to specify a field sort, but how do you think if you want to implement the ordering of multiple fields in a specified sequence?
How many fields are several? 2, 3 or more, so this uncertain factor needs to be ruled out.

Let's take a look at 2. Specify a scenario for sorting 2 fields:

  $arr = Array ('    0 ' = = Array (      ' id ' = = 3, ' age ' = '     ),    ' 1 ' = = Array (      ' id ' = = 5,      ' Age ' = ' +    ', ' 2 ' = = Array (      ' id ' = = 4,      ' age ' = '    ),    ' 3 ' = = Array (      ' ID ' = 3,      ' age ' = +    )   ;  foreach ($arr as $key = + $row) {    $id [$key] = $row [' id '];    $age [$key] = $row [' age '];  }  Array_multisort ($id, SORT_ASC, $age, Sort_desc, $arr);  Print_r ($arr);  Result:array ([' 0]=>array ' [' id ']=>3 [' age ']=>78] [1]=>array ([' ID ']=>3 [' age ']=>27] [2]=>array ([' ID ']=>4 [' Age ']=>44) [3]=>array ([' ID ']=>5 [' age ']=>50)]

Refactoring the above code, as long as the PHP Func_get_args function, to dynamically obtain the incoming value, can not only solve the problem of the number of multi-field uncertainties. The implementation is as follows:

  $array 1 = Array (        0=>array (' id ' =>8, ' name ' = ' Apple ', ' age ' = +),        1=>array (' id ' =>8, ' name ' = > ' Bed ', ' age ' =>17,        2=>array (' id ' =>5, ' name ' = ' Cos ', ' age ' =>16),        3=>array (' id ' =>5 , ' name ' = ' Cos ', ' age ' =>14)  ;  function Sortarrbymanyfield () {    $args = Func_get_args ();    if (empty ($args)) {      return null;    }    $arr = Array_shift ($args);    if (!is_array ($arr)) {      throw new Exception ("the first parameter is not an array");    }    foreach ($args as $key = + $field) {      if (is_string ($field)) {        $temp = array ();        foreach ($arr as $index = + $val) {          $temp [$index] = $val [$field];        }        $args [$key] = $temp;      }    }    $args [] = & $arr;//reference value    call_user_func_array (' Array_multisort ', $args);    Return Array_pop ($args);  }  $arr = Sortarrbymanyfield ($array 1, ' id ', SORT_ASC, ' name ', Sort_asc, ' age ', sort_desc);  Print_r ($arr);

The results of the operation are as follows:

Array (4) {
[0]=>array (3) {
["ID"]=>int (5)
["Name"]=>string (3) "Cos"
["Age"]=>int (16)
}
[1]=>array (3) {
["ID"]=>int (5)
["Name"]=>string (3) "Cos"
["Age"]=>int (14)
}
[2]=>array (3) {
["id"]=>int (8)
["Name"]=>string (5) "Apple"
["Age"]=>int (18)
}
[3]=>array (3) {
["id"]=>int (8)
["Name"]=>string (3) "Bed"
["Age"]=>int (17)
}
}

The above is the whole content of this article, I hope that everyone's learning has helped, but also hope that we support PHP Chinese network.

Articles you may be interested in:

PHP implementation of multi-image upload and single-image upload function php example

PHP implementation name sorted by initials class and method (instance code) PHP instance

PHP SMS Verification Code implementation process detailed PHP example