PHP Array Sort Summary with examples by William.

1. bool sort ( array &$array [, int $sort_flags= SORT_REGULAR ] ): Sort an array

   <?php
   //
   $fruits = array("lemon", "orange", "banana", "apple");
   sort($fruits);
   print\_r($fruits);
   ?>
   _Array
   (
   \[0\] => apple
   \[1\] => banana
   \[2\] => lemon
   \[3\] => orange
   )_

2. bool rsort ( array &$array [, int $sort_flags = SORT_REGULAR ] ): Sort an array in reverse order

   _Array
   (
   \[0\] => orange
   \[1\] => lemon
   \[2\] => banana
   \[3\] => apple
   )_

3. bool asort ( array &$array [, int $sort_flags = SORT_REGULAR ] ): Sort an array and maintain index association

   "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); asort($fruits); print\_r($fruits); ?>

   _Array
   (
   \[c\] => apple
   \[b\] => banana
   \[d\] => lemon
   \[a\] => orange
   )_ 

4. bool arsort ( array &$array [, int $sort_flags = SORT_REGULAR ] ):Sort an array in reverse order and maintain index association

   "lemon", "a" => "orange", "b" => "banana", "c" => "apple"); arsort($fruits); print\_r($fruits); ?>

   _Array
   (
   \[a\] => orange
   \[d\] => lemon
   \[b\] => banana
   \[c\] => apple
   )_ 

5. bool ksort ( array &$array [, int $sort_flags = SORT_REGULAR ] ):Sort an array by key

   "lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); ksort($fruits); print\_r($fruits); ?>

   _Array
   (
   \[a\] => orange
   \[b\] => banana
   \[c\] => apple
   \[d\] => lemon
   )_ 

6. bool krsort ( array &$array [, int $sort_flags = SORT_REGULAR ] ):Sort an array by key in reverse order

   "lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple"); krsort($fruits); print\_r($fruits); ?>

   _Array
   (
   \[d\] => lemon
   \[c\] => apple
   \[b\] => banana
   \[a\] => orange
   )_ 

7. bool usort ( array &$array , callback $cmp_function ):Sort an array by values using a user-defined comparison function

   _Array
   (
   \[0\] => 1
   \[1\] => 2
   \[2\] => 3
   \[3\] => 5
   \[4\] => 6
   )_ 

8. bool uksort ( array &$array , callback $cmp_function ):Sort an array by keys using a user-defined comparison function

   1, "the Earth" => 2, "an apple" => 3, "a banana" => 4); uksort($a, "cmp1"); print\_r($a); ?>

   _Array
   (
   \[an apple\] => 3
   \[a banana\] => 4
   \[the Earth\] => 2
   \[John\] => 1
   )_     

9. bool uasort ( array &$array , callback $cmp_function ):Sort an array with a user-defined comparison function and maintain index association

   4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4); // Sort and print the resulting array uasort($array, 'cmp2'); print\_r($array); ?>

   _Array
   (
   \[d\] => -9
   \[h\] => -4
   \[c\] => -1
   \[e\] => 2
   \[g\] => 3
   \[a\] => 4
   \[f\] => 5
   \[b\] => 8
   )_ 

10. bool array_multisort ( array &$arr [, mixed $arg = SORT_ASC [, mixed $arg = SORT_REGULAR [, mixed $… ]]] ):Sort multiple or multi-dimensional arrays

    _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_