PHP | Ds\Sequence slice() Function

The Ds\Sequence::slice() function is an inbuilt function in PHP which is used to return the subsequence of given range.

Syntax:

Ds\Sequence abstract public Ds\Sequence::slice ( int $index 
[, int $length ] )

Parameters: This function accepts two parameters as mentioned above and described below:

• $index: This parameter hold the starting index of subsequence. The index value can be positive and negative. If the index value is positive then it starts at the index of sequence and if the index value is negative then it sequence starts from ends.
• $length: This parameter holds the length of subsequence. This parameter can take positive and negative values. If length is positive then subsequence size is equal to a given length and if the length is negative then the sequence will stop that many values from the end.

Return value: This function returns the subsequence of given range.

Below programs illustrate the Ds\Sequence::slice() function in PHP:

Program 1:

<?php

// Create new sequence
$seq =  new \Ds\Vector([1, 3, 6, 9, 10, 15, 20]);

// Use slice() function to create
// sub sequence and display it
print_r($seq->slice(2));

print_r($seq->slice(1, 2));

print_r($seq->slice(2, -2));

?>

Output:

Ds\Vector Object
(
    [0] => 6
    [1] => 9
    [2] => 10
    [3] => 15
    [4] => 20
)
Ds\Vector Object
(
    [0] => 3
    [1] => 6
)
Ds\Vector Object
(
    [0] => 6
    [1] => 9
    [2] => 10
)

Program 2:

<?php

// Create new sequence
$seq =  new \Ds\Vector(["Geeks", "GFG", "Abc", "for"]);

// Use slice() function to create
// sub sequence and display it
print_r($seq->slice(3));

print_r($seq->slice(2, 0));

print_r($seq->slice(0, 3));

?>

Output:

Ds\Vector Object
(
    [0] => for
)
Ds\Vector Object
(
)
Ds\Vector Object
(
    [0] => Geeks
    [1] => GFG
    [2] => Abc
)

Reference: http://php.net/manual/en/ds-sequence.slice.php