PHP - Ds Sequence::get() Function

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The PHP Ds\Sequence::get() function is used to retrieve a value at a specified index in a sequence. The "index" represents the position of an element in the sequence, starting at 0. This means that an index value 0 represents the first element, 1 represents the second element, and so on.

If the specified index is invalid (i.e., negative or greater than the sequence size), it will throw an "OutOfRangeException".

Syntax

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

public abstract mixed Ds\Sequence::get( int $index )

Parameters

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

• index − The 0th-based index at which the values are searched.

Return value

This function returns the value at the specified index.

Example 1

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

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

Output

The above program produces the following output −

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

Example 2

Following is another example of the PHP Ds\Sequence::get() function. We use this function to retrieve a value at the specified index 2 in this sequence (["Tutorials", "Point", "Tutorix", "India"]) −

<?php 
   $seq = new \Ds\Vector(["Tutorials", "Point", "Tutorix", "India"]);
   echo "The sequence elements are: \n";
   print_r($seq);
   $index = 2;
   echo "The index is: ".$index;
   echo "\nThe value at index ".$index." is: ";
   #using get() function
   print_r($seq->get($index));
?>

Output

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

The sequence elements are:
Ds\Vector Object
(
    [0] => Tutorials
    [1] => Point
    [2] => Tutorix
    [3] => India
)
The index is: 2
The value at index 2 is: Tutorix

Example 3

If the specified index value is invalid, this function throws an "OutOfRangeException".

<?php 
   $seq = new \Ds\Vector(['a', 'e', 'i', 'o', 'u']);
   echo "The sequence elements are: \n";
   print_r($seq);
   $index = -1;
   echo "The index is: ".$index;
   echo "\nThe value at index ".$index." is: ";
   #using get() function
   print_r($seq->get($index));
?>

Output

The above program throws the following exception −

The sequence elements are:
Ds\Vector Object
(
    [0] => a
    [1] => e
    [2] => i
    [3] => o
    [4] => u
)
The index is: -1
The value at index -1 is: PHP Fatal error:  Uncaught OutOfRangeException: 
Index out of range: -1, expected 0 <= x <= 4 in C:\Apache24\htdocs\index.php:9
Stack trace:
#0 C:\Apache24\htdocs\index.php(9): Ds\Vector->get(-1)
#1 {main}
  thrown in C:\Apache24\htdocs\index.php on line 9