PHP Ds\Set reverse() Function

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The Ds\Set::reverse() function of Ds\Set class in PHP is an inbuilt function which is used to reverse the order of elements present in the Set instance. This function reverses the Set in-place. That is, it does not uses any extra space and updates the original Set instance with reversed values.

Syntax:

void public Ds\Set::reverse ( void )

Parameters: This function does not accepts any parameters.

Return Value: This function does not returns any value. It reverses the order of elements in the actual Set instance.

Below programs illustrate the Ds\Set::reverse() function:

Program 1:

<?php  
  
// Declare new Set 
$set = new \Ds\Set(["10", "20", "30"]);  
  
// Display the initial Set element  
echo "Initial Set: \n"; 
var_dump($set);  
  
// Reverse the set 
$set->reverse(); 
  
// Print the reversed Set 
echo "\nReversed Set is: \n"; 
var_dump($set); 
  
?>  

Output:

Initial Set: 
object(Ds\Set)#1 (3) {
  [0]=>
  string(2) "10"
  [1]=>
  string(2) "20"
  [2]=>
  string(2) "30"
}

Reversed Set is: 
object(Ds\Set)#1 (3) {
  [0]=>
  string(2) "30"
  [1]=>
  string(2) "20"
  [2]=>
  string(2) "10"
}

Program 2:

<?php  
  
// Declare new Set 
$set = new \Ds\Set(["Geeks", "for", "Keegs"]);  
  
// Display the initial Set element  
echo "Initial Set: \n"; 
var_dump($set);  
  
// Reverse the set 
$set->reverse(); 
  
// Print the reversed Set 
echo "\nReversed Set is: \n"; 
var_dump($set); 
  
?>  

Output:

Initial Set: 
object(Ds\Set)#1 (3) {
  [0]=>
  string(5) "Geeks"
  [1]=>
  string(3) "for"
  [2]=>
  string(5) "Keegs"
}

Reversed Set is: 
object(Ds\Set)#1 (3) {
  [0]=>
  string(5) "Keegs"
  [1]=>
  string(3) "for"
  [2]=>
  string(5) "Geeks"
}

Reference: http://php.net/manual/en/ds-set.reverse.php