PHP - Ds\Stack::copy() Function

The PHP Ds\Stack::copy() function is used to create and retrieve a shallow copy of the stack.

A shallow copy of a collection (or set) is a copy where the properties share the same references as those of the source object from which the copy was made.

Syntax

Following is the syntax of the PHP Ds\Stack::copy() function −

public Ds\Stack::copy(): Ds\Stack

Parameters

This function does not accept any parameter.

Return value

This function returns a shallow copy of the stack.

Example 1

The following program demonstrates the usage of the PHP Ds\Stack::copy() function −

<?php 
   $stack = new \Ds\Stack([10, 20, 30, 40, 50]);
   echo "The stack elements are: \n";
   print_r($stack);
   echo "The shallow copy of the stack is: \n";
   #using copy() function
   print_r($stack->copy());
?>

Output

The above program produces the following output −

The stack elements are:
Ds\Stack Object
(
    [0] => 50
    [1] => 40
    [2] => 30
    [3] => 20
    [4] => 10
)
The shallow copy of the stack is:
Ds\Stack Object
(
    [0] => 50
    [1] => 40
    [2] => 30
    [3] => 20
    [4] => 10
)

Example 2

Following is another example of the PHP Ds\Stack::copy() function. We use this function to retrieve a shallow copy of this stack (["Tutorials", "Point", "India"]) −

<?php 
   $stack = new \Ds\Stack([]);
   $stack->push("Tutorials", "Point", "India");
   echo "The stack elements are: \n";
   print_r($stack);
   echo "The shallow copy of the stack is: \n";
   #using copy() function
   print_r($stack->copy());
?>

Output

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

The stack elements are:
Ds\Stack Object
(
    [0] => India
    [1] => Point
    [2] => Tutorials
)
The shallow copy of the stack is:
Ds\Stack Object
(
    [0] => India
    [1] => Point
    [2] => Tutorials
)