PHP | Ds\Stack allocate() Function

The Ds\Stack::allocate() function is an inbuilt function in PHP which is used to allocate memory for required capacity. This function allocates sufficient memory for a given capacity of an instance of Stack class.
Syntax:

void Ds\Stack::allocate( $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 allocate.
Return Value: This function does not return any value.
Below programs illustrate the Ds\Stack::allocate() function in PHP:
Program 1:

php

<?php

// PHP program to illustrate the
// Ds\Stack::allocate() function

// Create a Stack instance
$stack = new \Ds\Stack();

echo("Allocated Space is: ");

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

echo("Allocated space is: ");

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

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

?>

Output:

Allocated Space is: int(8)
Allocated space is: int(50)

Program 2:

php

<?php

// Declare new stack
$stack = new \Ds\Stack();

echo("Allocated Space is: ");

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

echo("Allocated space is: ");

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

// Display the stack capacity
var_dump($stack->capacity());

echo("Allocated space is: ");

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

// Display the stack capacity
var_dump($stack->capacity());
?>

Output:

Allocated Space is: int(8)
Allocated space is: int(8)
Allocated space is: int(120)

Reference: https://www.php.net/manual/en/ds-stack.allocate.php