PHP arsort() function

PHP arsort() function

The arsort() function in PHP sorts an array in the reverse order and maintains the index association

Syntax

arsort ( array &$array [, int $sort_flags = SORT_REGULAR ] )

Parameter

array(required)- This parameter represents the input array.

sort_flags (optional)- This parameter is used to modify the behavior of the sort. The various possible values for sorting type flags are as follows:

  • SORT_REGULAR – It is used to compare items normally (don't change types)
  • SORT_NUMERIC – This flag is used to compare the items numerically.
  • SORT_STRING – It compares the given items as strings.
  • SORT_LOCALE_STRING – This flag compares the items as strings, based on the current locale.
  • SORT_NATURAL – It is used to compare items as strings using "natural ordering" like natsort().
  • SORT_FLAG_CASE – It can be combined (bitwise OR) with SORT_STRING or SORT_NATURAL to sort the given strings case-insensitively

Return

This function returns a Boolean value TRUE on success or FALSE on failure.

Example 1

"Reema", "Age"=>"23","Country"=>"India");
 //original array
 echo("Original array: \n");
 print_r($array);
 //sorting the array in reverse order and maintaining the index association
 arsort($array);
 //printing the reversed array 
 echo("\nReversed array: \n");
 print_r($array);
 ?> 

Output

Original array: 
 Array
 (
     [Name] => Reema
     [Age] => 23
     [Country] => India
 )
 Reversed array:  
 Array
 (
     [Name] => Reema
     [Country] => India
     [Age] => 23
 ) 

Example 2

 $val) {
     echo "fruits[" . $key . "] = " . $val . "\n";
 }
 //Sorting the array in reverse order and maintaining the index
 arsort($fruits); 
 echo("\n\nAfter sorting the array in reverse order...\n Reversed Array: \n");
 foreach ($fruits as $key => $val) {
     echo "fruits[" . $key . "] = " . $val . "\n";
 }
 ?> 

Output

Original Array: 
 fruits[0] = lemon
 fruits[1] = orange
 fruits[2] = banana
 fruits[3] = apple
 After sorting the array in reverse order...
  Reversed Array:  
 fruits[1] = orange
 fruits[0] = lemon
 fruits[2] = banana
 fruits[3] = apple 

Example 3

 array(1 => "mango", 2 => "banana", 2 => "apple"),
     "numbers" => array(1, 2, 3, 4, 5, 6),
     "values"   => array("first", 5 => "second", "third")
 );
 //sorting the array in reverse order maintaining the actual keys
 arsort($array); 
 //printing the reversed array
 print_r($array);
 ?> 

Output

Array
 (
     [numbers] => Array
         (
             [0] => 1
             [1] => 2
             [2] => 3
             [3] => 4
             [4] => 5
             [5] => 6 
         )
     [fruits] => Array
         (
             [1] => mango
             [2] => banana
             [3] => apple
         ) 
     [values] => Array
         (
             [0] => first
             [5] => second
             [6] => third
         )
 ) 

Example 4

"Reema", "Age"=>23,"Country"=>"India");
 //original array
 echo("Original array: \n");
 print_r($array);
 //sorting the array in reverse order while maintaining the index association
 arsort($array );
 //printing the sorted array
 echo("\nSorted array without the second parameter: \n");
 print_r($array); 
 //sorting array with second parameter as SORT_STRING in reverse order
 arsort($array,SORT_STRING  );
 //printing the sorted array
 echo("\nSorted array with the second parameter: \n");
 print_r($array);
 ?> 

Output

Original array: 
 Array
 (
     [Name] => Reema
     [Age] => 23
     [Country] => India
 ) 
 Sorted array without the second parameter: 
 Array
 (
     [Country] => India
     [Name] => Reema
     [Age] => 23
 )
 Sorted array with the second parameter:  
 Array
 (
     [Age] => 23
     [Country] => India
     [Name] => Reema
 )