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2.6. PHP Classes 类与对象

2.6.1. 构造函数和析构函数 __construct() / __destruct()

		
<?php
class MyClass {
   function __construct() {
       print "In constructor\n";
       $this->name = "MyClass";
   }

   function __destruct() {
       print "Destroying " . $this->name . "\n";
   }
}

$obj = new MyClass();
?>
		
		
		
class Members extends Common{

	public function __construct() {
		parent::__construct();
	}
}
		
		

2.6.2. Traits

http://php.net/manual/en/language.oop5.traits.php

		
<?php
class Base {
    public function sayHello() {
        echo 'Hello ';
    }
}

trait SayWorld {
    public function sayHello() {
        parent::sayHello();
        echo 'World!';
    }
}

class MyHelloWorld extends Base {
    use SayWorld;
}

$o = new MyHelloWorld();
$o->sayHello();
?>


<?php
trait HelloWorld {
    public function sayHello() {
        echo 'Hello World!';
    }
}

class TheWorldIsNotEnough {
    use HelloWorld;
    public function sayHello() {
        echo 'Hello Universe!';
    }
}

$o = new TheWorldIsNotEnough();
$o->sayHello();
?>
		
		

Multiple Traits

		
<?php
trait Hello {
    public function sayHello() {
        echo 'Hello ';
    }
}

trait World {
    public function sayWorld() {
        echo 'World';
    }
}

class MyHelloWorld {
    use Hello, World;
    public function sayExclamationMark() {
        echo '!';
    }
}

$o = new MyHelloWorld();
$o->sayHello();
$o->sayWorld();
$o->sayExclamationMark();
?>
		
		

Conflict Resolution

		
<?php
trait A {
    public function smallTalk() {
        echo 'a';
    }
    public function bigTalk() {
        echo 'A';
    }
}

trait B {
    public function smallTalk() {
        echo 'b';
    }
    public function bigTalk() {
        echo 'B';
    }
}

class Talker {
    use A, B {
        B::smallTalk insteadof A;
        A::bigTalk insteadof B;
    }
}

class Aliased_Talker {
    use A, B {
        B::smallTalk insteadof A;
        A::bigTalk insteadof B;
        B::bigTalk as talk;
    }
}
?>
		
		

Changing Method Visibility

		
<?php
trait HelloWorld {
    public function sayHello() {
        echo 'Hello World!';
    }
}

// Change visibility of sayHello
class MyClass1 {
    use HelloWorld { sayHello as protected; }
}

// Alias method with changed visibility
// sayHello visibility not changed
class MyClass2 {
    use HelloWorld { sayHello as private myPrivateHello; }
}
?>
		
		

Traits Composed from Traits

		
<?php
trait Hello {
    public function sayHello() {
        echo 'Hello ';
    }
}

trait World {
    public function sayWorld() {
        echo 'World!';
    }
}

trait HelloWorld {
    use Hello, World;
}

class MyHelloWorld {
    use HelloWorld;
}

$o = new MyHelloWorld();
$o->sayHello();
$o->sayWorld();
?>		
		
		

2.6.3. Example

2.6.3.1. Method

例 2.1. 动态增加方法

				
				
<?php
class stdObject {
    public function __construct(array $arguments = array()) {
        if (!empty($arguments)) {
            foreach ($arguments as $property => $argument) {
                if ($argument instanceOf Closure) {
                    $this->{$property} = $argument;
                } else {
                    $this->{$property} = $argument;
                }
            }
        }
    }

    public function __call($method, $arguments) {
        if (isset($this->{$method}) && is_callable($this->{$method})) {
            return call_user_func_array($this->{$method}, $arguments);
        } else {
            throw new Exception("Fatal error: Call to undefined method stdObject::{$method}()");
        }
    }
}

$person = new stdObject(array(
    "name" => "nick",
    "age" => 23,
    "friends" => array("frank", "sally", "aaron"),
    "sayHi" => function() {
        return "Hello there";
    }
));

$person->sayHi2 = function() {
    return "Hello there 2";
};

$person->test = function() {
    return "test";
};

var_dump($person->name, $person->test(), $person->sayHi2());
?>				
				
				

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