PHP Ds\Queue allocate() Function

The Ds\Queue::allocate() Function in PHP is used to allocate memory for a Queue class instance. This function allocates sufficient memory for a given capacity for an instance of Queue class.

Syntax:

void public Ds\Queue::allocate ( int $capacity )

Parameters: This function accepts a single parameter $capacity which is an integral value denoting the number of values for which capacity is needed to be allocated.

Return Value: This method does not returns any value.

Below programs illustrate the Ds\Queue::allocate() function in PHP:

Program 1:

<?php

// Declare new PriorityQueue
$pq = new \Ds\PriorityQueue();

echo("Allocated Space is: ");

// Use capacity() function
var_dump($pq->capacity());

echo("Allocated space is: ");

// Use allocate() function to
// allocate capacity
$pq->allocate(50);

// Display the allocated vector
// capacity
var_dump($pq->capacity());

?>

Output:

Allocated Space is: int(8)
Allocated space is: int(64)

Program 2:

<?php

// Declare new Queue
$q = new \Ds\Queue();

echo("Allocated Space is: ");

// Use capacity() function
var_dump($q->capacity());

echo("Allocated space is: ");

// Use allocate() function to
// allocate capacity
$q->allocate(5);

// Display the allocated vector
// capacity
var_dump($q->capacity());

// Use allocate() function to
// allocate capacity
$q->allocate(120);

// Display the allocated vector
// capacity
var_dump($q->capacity());

?>

Output:

Allocated Space is: int(8)
Allocated space is: int(8)
int(128)

Reference: http://php.net/manual/en/ds-queue.allocate.php