Getting Started with PHP, clone and __clone

Objective

This article mainly introduces PHP programming in the __clone () method using the detailed, __clone () method equivalent to a shallow copy, is the basic knowledge of PHP primer learning, the need for friends can refer to.

1 objects are reference data types, when you assign an object to another object by using =, the address of the object is assigned, two variables point to the same address, and the other one changes

__construct () Function: Creates a new SimpleXMLElement object. If successful, the function returns an object. If it fails, it returns false.

Original $zhangsan:

Class person{public    $name;    public $age;    function __construct ($name, $age) {        $this->name= $name;        $this->age= $age;    }} $zhangsan =new person ("Zhang San"), Var_dump ($zhangsan);

Set up a Lisi

$lisi = $zhangsan;

Set the age of Lisi to 28.

$lisi->age=28;

Printing Zhang San and John Doe at the same time will show:

2clone: If you want to completely clone an object to a non-interfering object, you need to use the Clone keyword;

Put John Doe clone Zhang San and set age to 28.

$lisi =clone $zhangsan; $lisi->age=28;

Print Zhang San and John Doe at this time.

3__clone ();

① the Magic method is automatically invoked when cloning an object using the Clone keyword;
The ②__clone () function, which is equivalent to the constructor for cloning an object, is used to assign an initial value to a new cloned object;
③ in the Clone () function, the $this points to the object that is new to Cologne.

function __clone () {        echo "execute clone command <br>";        $this->name= "John Doe";    }

@ Only Yun Hee

Getting Started with PHP, clone and __clone