PHP Magic Method: __clone __tostring

From the later version of PHP5, the class will be able to use the Magic method. PHP rules to start with two underscore (__) methods are preserved as a magic method, it is recommended that the function name is best not to start without __, unless it is to reload the existing magic method.

At present, PHP has a magic method has __construct,__destruct,__call,__get,__set,__isset,__unset,__sleep,__wakeup,__tostring,__set_state and __clone.

Let's take a look at two magic methods:__clone () and __tostring ().

__clone ()-Automatically load this method when the object is cloned

__tostring ()-Automatically loads this method when an object needs an echo print output

__clone ()

 
  PB = ++self:: $pa;    }        Public Function __clone () {        $this->PB = ' no Zuo no die ';    }} $a = new example; $b = new example; $c = Clone $b; $b->pb = ' I love your so much! '; echo $a->pb;echo '
 
  ' Echo $b->pb;echo '
 
  ' Echo $c->pb;echo '
 
  '; echo $b->PB;? >

The results are as follows

1 ------------------------------------------------------------------------------------------ ---------------------------------------------------------------------------------------------------- -------------------------------------------------------------- I Love much!

The PHP manual gives us an example that is somewhat difficult to read, as follows

 
  Instance = ++self:: $instances;    }    Public Function __clone () {        $this->instance = ++self:: $instances;    }} Class mycloneable{public    $object 1;    Public $object 2;    function __clone ()    {              //forces a copy of This->object, otherwise it still points to the same object        $this->object1 = Clone $this->object1 ;    }} $obj = new Mycloneable (), $obj->object1 = new Subobject (), $obj->object2 = new Subobject (), $obj 2 = Clone $obj;p rint ("O Riginal object:\n ");p Rint_r ($obj);p rint (" Cloned object:\n ");p Rint_r ($obj 2);? >

The final result

Object Object (Object  (            1  )          Object (            2objectobject  (      Object  (            /* may be more difficult to understand here, in fact, it is $obj2 when cloning the final instance as 2 of the result of cloning, and then execute the Subobject::__clone method */  )    Object  (            2  ))

__tostring ()

 
  foo = $foo;    }    Public Function __tostring () {        return $this->foo;    }} $class = new TestClass (' Hello '); Echo $class;? >

Results

Hello

The above describes the PHP magic method: __clone __tostring, including the PHP magic method of content, I hope that the PHP tutorial interested in a friend helpful.

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