In-depth analysis of object-oriented PHP_PHP tutorial
In the past, object-orientation was limited to rote memorization. After working for so long, looking back, I have gained another understanding for everyone to see.
1.final
final: php5 adds a new final keyword. If a method in the parent class is declared final, the subclass cannot override the method; if a class is declared final, it cannot be inherited.
class BaseClass{
public function test(){
ehco "test ";
}
final public function moreTest(){
echo "moretest";
}
}
class ChildClass extends BaseClass{
public function moreTest(){
Echo "moretest"; 🎜>
2.__toString (PHP5.2 or higher is recommended)
Copy code
The code is as follows:
public function setEmail($email){
> return "$this->name email>";
);
$rasums->setEmail('test@qq.com');
print $rasums;
3. Interfaces and abstract classes
The role of interface: You want to ensure that a class implements one or more methods with a specific name, visibility, and prototype.
Interface requirements:
All methods in the class are abstract methods
There is no need to add abstract for abstract methods
The abstract method attributes of the interface are public
Example:
Copy code
The code is as follows:
interface ChildTest{
public function childTest ();
}
class FathTest implements ChildTest1,ChildTest2{
public function childTest(){ echo 1;
}
There must be at least one abstract method in the class
The abstract method must be added abstract
Example:
Copy code
The code is as follows:
abstract class Database{ abstract public function connect(); abstract public function query();
abstract public function fetch();
abstract public function close();}
Note: Abstract methods cannot be defined as private methods or final methods because they need to be inherited.
4. Pass object reference
php4: All "="s create a copy
php5: Except for objects, other "="s When assigning a value, a copy is created; while the object is a reference
5. Clone object
1.
Aggregation class :
Introduction to the __call method:
When the client code uses an undefined method in the class, __call will be called.
__call() accepts two parameters, one is the method name, and the other is all parameters (including arrays) passed to the method to be called.
Any value returned by the __call() method will be returned to the client and will be as if called The method really exists
Example:
class Address{
protected $city ;
protected $country;
public function setCity($city){$this->city = $city;}
public function getCity(){return $this->city;}
public function setCountry($country) {$this->country = $country;}
public function getCountry(){return $this->country;}
}
class Person{
protected $name;
protected $address;
//Shallow clone
public function __construct(){
$this->address = new Address;
}
public function setName($name){
$this->name = $name;
}
public function getName(){
return $this->name;
}
public function __call($method,$arguments){
if(method_exists($this->address,$method)){
return call_user_func_array(array($this->address,$method) ; > }
}
$test1 = new Person;
$test2 = clone $test1;
$test1->setName('testname1');
$test1->setCity('testcity1');
$test2 ->setCity('testcity2');
echo $test2->getName().'-'.$test2- >getCity()."n";
//testname1-testcity2
//testname2-testcity2
6. Important attribute access (__set __get __isset __unset) __isset __unset is only useful after 5.1
Example:
Copy code
The code is as follows:
class Person{
protected $__data = array('email','test');
public function __get($property){
if(isset($this->__data[$property])){
return $this->__data[$property];
}else{
return false;
}
}
public function __set($property,$value){
if(isset($this->__data[$property])){
return $this->__data[$property] = $value;
}else{
return false;
}
}
public function __isset($property){
if(isset($this->__data[$property])){
return true;
}else{
return false;
}
}
public function __unset($property){
if(isset($this->__data[$property])){
return unset($this->__data[$property]);
}else{
return false;
}
}
}
$test = new Person;
$test->email= 'test';
var_dump($test->email);
注意:
这两个方法只会捕捉缺少的属性,如果你为你的类定义了一个属性,那么当访问这个属性时php不会调用__get()和__set();
这两个方法完全破坏了任何属性继承的想法。如果父对象中有个 __get()方法,而你在子类中又实现了自己的__get()方法,那么你的对象不会正确的执行,因为父类的__get()方法永远不会被调用,当然可以用parent::__get()解决
缺点:
速度相对较慢
使用魔术访问器方法就不可能在使用反射类,如phpdocumentor这类的工具将代码自动文档化
不能将其用于静态属性

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