16 の PHP マジック メソッドを紹介します

function __constrct([parameter list]){ 方法具体实现 //通常为成员变量初始赋值。 }

name = $name; $this->sex = $sex; $this->age = $age; } /** * say 方法定义 */ public function say() { echo "Name：" . $this->name . ",Sex：" . $this->sex . ",Age：" . $this->age; } }

$Person1 = new Person(); echo $Person1->say(); //显示：Name：,Sex：Male,Age：22

$Person2 = new Person("Jams"); echo $Person2->say(); // 显示： Name: Jams, Sex: Male, Age: 22

$Person3 = new Person ("Jack", "Male", 25); echo $Person3->say(); // 显示：Name: Jack, Sex: Male, Age: 25

function __destruct() { //method body }

name = $name; $this->sex = $sex; $this->age = $age; } /** * say method */ public function say() { echo "Name：".$this->name.",Sex：".$this->sex.",Age：".$this->age; } /** * declare a destructor method */ public function __destruct() { echo "Well, my name is ".$this->name; } } $Person = new Person("John"); unset($Person); //destroy the object of $Person created above

Well, my name is John

function __call(string $function_name, array $arguments) { // method body }

"; } function __call($funName, $arguments) { echo "The function you called：" . $funName . "(parameter：" ; // Print the method's name that is not existed. print_r($arguments); // Print the parameter list of the method that is not existed. echo ")does not exist!！
\n"; } } $Person = new Person(); $Person->run("teacher"); // If the method which is not existed is called within the object, then the __call() method will be called automatically. $Person->eat("John", "apple"); $Person->say();

The function you called: run (parameter: Array([0] => teacher)) does not exist! The function you called: eat (parameter: Array([0] => John[1] => apple)) does not exist! Hello world!

"; } public static function __callStatic($funName, $arguments) { echo "The static method you called：" . $funName . "(parameter：" ; // 打印出未定义的方法名。 print_r($arguments); // 打印出未定义方法的参数列表。 echo ")does not exist！
\n"; } } $Person = new Person(); $Person::run("teacher"); // 如果此项目内不存在的方法被调用了，那么 __callStatic() 方法将被自动调用。 $Person::eat("John", "apple"); $Person->say();

The static method you called: run (parameter: Array([0] => teacher)) does not exist! The static method you called: eat (parameter: Array([0] => John[1] => apple)) does not exist! Hello world!

name = $name; $this->age = $age; } public function __get($propertyName) { if ($propertyName == "age") { if ($this->age > 30) { return $this->age - 10; } else { return $this->$propertyName; } } else { return $this->$propertyName; } } } $Person = new Person("John", 60); // Instantiate the object with the Person class and assign initial values to the properties with the constructor. echo "Name：" . $Person->name . "
"; // When the private property is accessed, the __get() method will be called automatically,so we can get the property value indirectly. echo "Age：" . $Person->age . "
"; // The __get() method is called automatically，and it returns different values according to the object itself.

Name: John Age: 50

name = $name; $this->age = $age; } public function __set($property, $value) { if ($property=="age") { if ($value > 150 || $value < 0) { return; } } $this->$property = $value; } public function say(){ echo "My name is ".$this->name.",I'm ".$this->age." years old"; } } $Person=new Person("John", 25); //请注意，类初始化并为“name”和“age”分配初始值。 $Person->name = "Lili"; // "name" 属性值被成功修改。如果没有__set()方法，程序将报错。 $Person->age = 16; // "age"属性修改成功。 $Person->age = 160; //160是无效值，因此修改失败。 $Person->say(); //输出:My name is Lili, I'm 16 years old。

My name is Lili, I'm 16 years old

name = $name; $this->age = $age; $this->sex = $sex; } /** * @param $content * * @return bool */ public function __isset($content) { echo "The {$content} property is private，the __isset() method is called automatically.
"; echo isset($this->$content); } } $person = new Person("John", 25); // Initially assigned. echo isset($person->sex),"
"; echo isset($person->name),"
"; echo isset($person->age),"
";

1 The name property is private，the __isset() method is called automatically. 1 The age property is private，the __isset() method is called automatically. 1

name = $name; $this->age = $age; $this->sex = $sex; } /** * @param $content * * @return bool */ public function __unset($content) { echo "It is called automatically when we use the unset() method outside the class.
"; echo isset($this->$content); } } $person = new Person("John", 25); // Initially assigned. unset($person->sex),"
"; unset($person->name),"
"; unset($person->age),"
";

It is called automatically when we use the unset() method outside the class. 1 It is called automatically when we use the unset() method outside the class. 1

name = $name; $this->age = $age; $this->sex = $sex; } /** * @return array */ public function __sleep() { echo "It is called when the serialize() method is called outside the class.
"; $this->name = base64_encode($this->name); return array('name', 'age'); // It must return a value of which the elements are the name of the properties returned. } } $person = new Person('John'); // Initially assigned. echo serialize($person); echo '
';

It is called when the serialize() method is called outside the class. O:6:"Person":2:{s:4:"name";s:8:"5bCP5piO";s:3:"age";i:25;}

name = $name; $this->age = $age; $this->sex = $sex; } /** * @return array */ public function __sleep() { echo "It is called when the serialize() method is called outside the class.
"; $this->name = base64_encode($this->name); return array('name', 'age'); // It must return a value of which the elements are the name of the properties returned. } /** * __wakeup */ public function __wakeup() { echo "It is called when the unserialize() method is called outside the class.
"; $this->name = 2; $this->sex = 'Male'; // There is no need to return an array here. } } $person = new Person('John'); // Initially assigned. var_dump(serialize($person)); var_dump(unserialize(serialize($person)));

It is called when the serialize() method is called outside the class. string(58) "O:6:"Person":2:{s:4:"name";s:8:"5bCP5piO";s:3:"age";i:25;}" It is called when the unserialize() method is called outside the class. object(Person)#2 (3) { ["sex"]=> string(3) "Male" ["name"]=> int(2) ["age"]=> int(25) }

name = $name; $this->age = $age; $this->sex = $sex; } public function __toString() { return 'go go go'; } } $person = new Person('John'); // Initially assigned. echo $person;

go go go

name = $name; $this->age = $age; $this->sex = $sex; } } $person = new Person('John'); // Initially assigned. echo $person;

Catchable fatal error: Object of class Person could not be converted to string in D:\phpStudy\WWW\test\index.php on line 18

name = $name; $this->age = $age; $this->sex = $sex; } public function __invoke() { echo 'This is an object'; } } $person = new Person('John'); // Initially assigned. $person();

This is an object

Fatal error: Function name must be a string in D:\phpStudy\WWW\test\index.php on line 18

name = $name; $this->age = $age; $this->sex = $sex; } } $person = new Person('John'); // Initially assigned. var_export($person);

Person::__set_state(array( 'sex' => 'Male', 'name' => 'John', 'age' => 25, ))

name = $name; $this->age = $age; $this->sex = $sex; } public static function __set_state($an_array) { $a = new Person(); $a->name = $an_array['name']; return $a; } } $person = new Person('John'); // Initially assigned. $person->name = 'Jams'; var_export($person);

Person::__set_state(array( 'sex' => 'Male', 'name' => 'Jams', 'age' => 25, ))

$copy_of_object = clone $object;

name = $name; $this->age = $age; $this->sex = $sex; } public function __clone() { echo __METHOD__."your are cloning the object.
"; } } $person = new Person('John'); // Initially assigned. $person2 = clone $person; var_dump('persion1:'); var_dump($person); echo '
'; var_dump('persion2:'); var_dump($person2);

Person::__clone your are cloning the object. string(9) "persion1:" object(Person)#1 (3) { ["sex"]=> string(3) "Male" ["name"]=> string(6) "John" ["age"]=> int(25) } string(9) "persion2:" object(Person)#2 (3) { ["sex"]=> string(3) "Male" ["name"]=> string(6) "John" ["age"]=> int(25) }

/** * file non_autoload.php */ require_once('project/class/A.php'); require_once('project/class/B.php'); require_once('project/class/C.php'); . . . if (ConditionA) { $a = new A(); $b = new B(); $c = new C(); // … } else if (ConditionB) { $a = newA(); $b = new B(); // … }

/** * file autoload_demo.php */ function __autoload($className) { $filePath = “project/class/{$className}.php”; if (is_readable($filePath)) { require($filePath); } } if (ConditionA) { $a = new A(); $b = new B(); $c = new C(); // … } else if (ConditionB) { $a = newA(); $b = new B(); // … }

prop = $val; } /** * @return array */ public function __debugInfo() { return [ 'propSquared' => $this->prop ** 2, ]; } } var_dump(new C(42));

object(C)#1 (1) { ["propSquared"]=> int(1764) }