Php tutorial array_multisort () function details
Function bool array_multisort (array & $ arr [, mixed $ arg = SORT_ASC [, mixed $ arg = SORT_REGULAR [, mixed $...])
Parameter description: The function sorts multiple arrays or multi-dimensional arrays.
The first parameter is an array, and each subsequent parameter may be an array or the following sort order mark.
SORT_ASC-default, in ascending order
SORT_DESC-sort in descending order
You can specify the sorting type.
SORT_REGULAR-default. Sort each item in the general order.
SORT_NUMERIC-Sort each item in numerical order.
SORT_STRING-Sort each item in alphabetical order.
Instance code
$ Arr1 = array ('10', 11,100,100, 'A ');
$ Arr2 = array (1, 2, 3, '2', 5 );
Array_multisort ($ arr1, $ arr2 );
Result:
$ Arr1
Array ([0] => 10 [1] => a [2] => 11 [3] => 100 [4] => 100)
# '10' is converted to an integer 10 when compared with 11,100,100, which is smaller than the other three.
# '10' is a string when 'A' is compared. Its first character '1' ascii code value is 49 less than 'A' (ascii value is 97 ), therefore, '10' is the minimum element.
# When 'A' is compared with the other three numbers, it is converted to an integer 0, which is smaller than the other three.
$ Arr2
Array ([0] => 1 [1] => 5 [2] => 2 [3] => 2 [4] => 3)
# $ Arr2 element 1 corresponds to $ arr1 element '10', so it is in the [0] position.
# $ Arr1 [2] => 100, $ arr1 [3] => 100 corresponds to $ arr2 element 3, '2' respectively '. 3 is greater than '2'. Therefore, the subscript corresponding to $ arr1 [2] => 100 after sorting is
3. The subscript of $ arr1 [3] => 100 sorting is 4.
Summary
1. The number of elements in the array to be sorted must be consistent.
2. The position of the elements in the sorting array corresponds to, for example, '10' => 1, 11 => 2.
3. The back array is sorted based on the order of the front array.
4. In case of equal elements, the array of the front edge compares the Array
Syntax
array_multisort(array1,sorting order,sorting type,array2,array3...)
Parameters |
Description |
Array1 |
Required. Specifies the input array. |
Sorting order |
Optional. Specify the order. Possible values are SORT_ASC and SORT_DESC. |
Sorting type |
Optional. Specifies the sorting type. Possible values are SORT_REGULAR, SORT_NUMERIC, and SORT_STRING. |
Array2 |
Optional. Specifies the input array. |
Array3 |
Optional. Specifies the input array. |
Tips and comments
Note: The string key will be retained, but the number key will be re-indexed, starting from 0 and increasing at 1.
Note: You can set the sorting order and type behind each array. If no value is set, the default value is used for each array parameter.