PHP - Ds Deque::get() Function

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The PHPDs\Deque::get()function is used to retrieve an element from the current deque at the specified index. The "index" is the position of the element in a deque starting at 0, representing the first element, 1 representing the second, and so on.

If the specified index is invalid (i.e., is negative or larger than the deque size), this function throws an 'OutOfRangeException'.

Syntax

Following is the syntax of the PHP Ds\Deque::get() function −

public Ds\Deque::get(int $index): mixed 

Parameters

This function accepts a single parameter named 'index', which is described below −

• index − A 0th-based index at which the element to search.

Return value

This function returns an element at the specified index.

Example 1

The following program demonstrates the usage of the PHP Ds\Deque::get() function −

<?php
   $deque = new \Ds\Deque([10, 20, 30, 40, 50]);
   echo "The deque elements are: \n";
   print_r($deque);
   $index = 0;
   echo "The index value is: ".$index;
   echo "\nThe element at index ".$index." is: ";
   #using get() function
   print_r($deque->get($index));
?>

Output

The above program returns the element of the 3rd index as:

The deque elements are:
Ds\Deque Object
(
    [0] => 10
    [1] => 20
    [2] => 30
    [3] => 40
    [4] => 50
)
The index value is: 0
The element at index 0 is: 10

Example 2

The following is another example of the PHP Ds\Deque::get() function. We use this function to retrieve an element at the specified index 0 in this deque (["Tutorials", "Point", "India", "Tutorix"]) −

<?php
   $deque = new \Ds\Deque(["Tutorials", "Point", "India", "Tutorix"]);
   echo "The deque elements are: ";
   print_r($deque);
   $index = 0;
   echo "The given index is: ".$index;
   echo "\nThe element find at index ".$index." is: ";
   var_dump($deque->get($index));
?>

Output

After executing the above program, it will display the following output −

The deque elements are: Ds\Deque Object
(
    [0] => Tutorials
    [1] => Point
    [2] => India
    [3] => Tutorix
)
The given index is: 0
The element find at index 0 is: string(9) "Tutorials"

Example 3

If the specified index value is -1, this function will throw an 'OutOfRangeException' exception.

In the example below, we use the PHP Ds\Deque::get() function to retrieve an element at the specified index -1 in this deque ([1, 1, 2, 3, 5]) −

<?php
   $deque = new \Ds\Deque([1, 2, 3, 4, 5]);
   echo "The deque elements are: \n";
   print_r($deque);
   $index = -1;
   echo "The given index is: ".$index;
   echo "\nThe element at index ".$index." is: /n";
   print_r($deque->get($index));
?>

Output

On executing the above program, it will throw an exception as:

The deque elements are:
Ds\Deque Object
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 5
)
The given index is: -1
The element at index -1 is: /nPHP Fatal error:  Uncaught OutOfRangeException: 
Index out of range: -1, expected 0 <= x <= 4 in C:\Apache24\htdocs\index.php:8
Stack trace:
#0 C:\Apache24\htdocs\index.php(8): Ds\Deque->get(-1)
#1 {main}
  thrown in C:\Apache24\htdocs\index.php on line 8