What is diffrence between CLONE and copying the object?

Does it make any difference if i copy object by simply assign it to another object instead of开发者_StackOverflow社区 clone it?

If you simple assign it, like:

$obj2 = $obj;

then you don't copy the object. You copy the reference to the object. Thus, $obj2 and $obj point to the same object.

See also Objects and references

Example:

class A {
  public $foo = 'bar'; 
}

$obj = new A();
$obj2 = $obj;

$obj2->foo = 'foo too';

echo $obj->foo . PHP_EOL;

$obj = new A();
$obj2 = clone($obj);

$obj2->foo = 'foo too';

echo $obj->foo . PHP_EOL;

prints

foo too
bar

DEMO

In addition to Felix Kling's answer, using clone enables usage of __clone() magic method.

class Obj{
   public $cloned = 0;
   public function __clone(){
      $this->cloned++;
   }
}

$obj1 = new Obj();
$obj2 = $obj1;
echo 'Times cloned: ' . $obj2->cloned; // returns 'Times cloned: 0'
var_dump($obj2 === $obj1); // true

$obj3 = clone $obj1;
echo 'Times cloned: ' . $obj3->cloned; // returns 'Times cloned: 1'
var_dump($obj3 === $obj1); // false