PHP - Ds Deque::find() Function

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The PHPDs\Deque::find()function is used to retrieve the index of a given value in the current deque. If the specified value exists in the deque, it returns the index of the value; if not, it returns 'false'.

The index is the position of the element starting at 0 representing the first element, 1 representing the second element, and so on.

Syntax

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

public Ds\Deque::find(mixed $value): mixed

Parameters

Following is the parameter of this function −

• value − It represents an integer value which specifies the value to find.

Return value

This function returns the index of the value if found; otherwise, it returns 'false'.

Example 1

The following is the basic example of the PHP Ds\Deque::find() function −

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

Output

The above program produces the following output −

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

Example 2

Following is another example of the PHP Ds\Deque::find() function. We use this function to retrieve the index of the value 'o' in this deque (['a', 'e', 'i', 'o', 'u')] −

<?php
   $deque = new \Ds\Deque(['a', 'e', 'i', 'o', 'u']);
   echo "The deque elements are: \n";
   print_r($deque);
   $val = 'o';
   echo "The given value is: ".$val;
   echo "\nThe index of the element ".$val."is: ";
   #using find() function
   print_r($deque->find($val));
?>

Output

After executing the above program, it displays the following output −

The deque elements are:
Ds\Deque Object
(
    [0] => a
    [1] => e
    [2] => i
    [3] => o
    [4] => u
)
The given value is: o
The index of the element ois: 3

Example 3

If the specified value'kiwi'does not found in this deque (["apple", "banana", "orange", "grapes"]), this function will return 'false' in the output as follows:

<?php
   $deque = new \Ds\Deque(["apple", "banana", "orange", "grapes"]);
   echo "The deque elements are: \n";
   print_r($deque);
   $val = "Kiwi";
   echo "The given value is: ".$val;
   echo "\nThe index of the element ".$val." is: ";
   var_dump($deque->find($val));
?>

Output

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

The deque elements are:
Ds\Deque Object
(
    [0] => apple
    [1] => banana
    [2] => orange
    [3] => grapes
)
The given value is: Kiwi
The index of the element Kiwi is: bool(false)