PHP - Ds Sequence::reverse() Function

The PHP Ds\Sequence::reverse() function is used to reverse a sequence in-place. The term 'in-place' refers that the reversal is done without creating or allocating memory for a new sequence, instead, this function modifies the existing sequence directly.

Syntax

Following is the syntax of the PHP Ds\Sequence::reverse() function −

public abstract void Ds\Sequence::reverse( void )

Parameters

This function does not accept any parameter.

Return value

This function does not return any value.

Example 1

The following is the basic example of the PHP Ds\Sequence::reverse() function −

<?php  
   $seq = new \Ds\Vector([1, 2, 3, 4, 5]);  
   echo("The original sequence before reversing: \n");  
   print_r($seq);
   echo("The Sequence after reversing: \n");
   #using reverse() function   
   $seq->reverse();
   print_r($seq); 
?>

Output

The above program produces the following output −

The original sequence before reversing:
Ds\Vector Object
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)
The Sequence after reversing:
Ds\Vector Object
(
    [0] => 5
    [1] => 4
    [2] => 3
    [3] => 2
    [4] => 1
)

Example 2

Following is another example of the PHP Ds\Sequence::reverse() function. We use this function to reverse the order of this sequence (["Tutorials", "Point", "India"]) elements −

<?php  
   $seq = new \Ds\Vector(["Tutorials", "Point", "India"]); 
   echo("The original Sequence before reversing: \n");  
   print_r($seq);  
   echo("The Sequence after reversing: \n");
   #using reverse() function
   $seq->reverse(); 
   print_r($seq); 
?>

Output

After executing the above program, the following output will be displayed −

The original Sequence before reversing:
Ds\Vector Object
(
    [0] => Tutorials
    [1] => Point
    [2] => India
)
The Sequence after reversing:
Ds\Vector Object
(
    [0] => India
    [1] => Point
    [2] => Tutorials
)