Sorting an array

PHP has some functions for sorting arrays, and this document lists them.

The main differences are:

• Some functions are sorted based on the keys of the array, while others are sorted based on values:$array [' key '] = ' value ';.
• Whether the association between the key and the value can be persisted after sorting means that the key of the array after sorting may be reset to digital type (0,1,2 ... ）。
• The order of sorting is: alphabetical order, from low to High (ascending), from high to low (descending), numeric sort, natural sort, random order or user-defined sort.
• Note: All of the following sorting functions are directly acting on the array itself, rather than returning a new ordered array.
• The following functions are not defined in the order in which they are sorted, for elements that are equal in the array. (That is, the order between the equal elements is not stable).

Sort function Properties

Function Name	sort on	array index key hold	Order of sorts	related Functions
Array_multisort ()	Value	Retention of key-value associations, non-retention of numeric types	The first array is either specified by an option	Array_walk ()
Asort ()	Value	Is	From low to high	Arsort ()
Arsort ()	Value	Is	From high to Low	Asort ()
Krsort ()	Key	Is	From high to Low	Ksort ()
Ksort ()	Key	Is	From low to high	Asort ()
Natcasesort ()	Value	Is	Natural sort, case insensitive	Natsort ()
Natsort ()	Value	Is	Natural sort	Natcasesort ()
Rsort ()	Value	Whether	From high to Low	Sort ()
Shuffle ()	Value	Whether	Random	Array_rand ()
Sort ()	Value	Whether	From high to Low	Rsort ()
Uasort ()	Value	Is	Defined by user	Uksort ()
Uksort ()	Key	Is	Defined by user	Uasort ()
Usort ()	Value	Whether	Defined by user	Uasort ()

http://php.net/manual/zh/array.sorting.php

Sorting an array