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How to use __call() in PHP

墨辰丷
墨辰丷Original
2018-05-16 14:35:303310browse

This article mainly introduces the use of __call() in PHP. Interested friends can refer to it. I hope it will be helpful to everyone.

PHP5 objects have a new special method __call(), which is used to monitor other methods in an object. If you try to call a method that does not exist in an object or is permission-controlled, the __call method will be automatically called.

Example 1: __call

<?php  
class foo {  
  function __call($name,$arguments) {  
    print("Did you call me? I&#39;m $name!");  
  }  
} $x = new foo();  
$x->doStuff();  
$x->fancy_stuff();  
?>

This special method can be used to implement the "overloading" action in JAVA, so that you can check your parameters and Pass parameters by calling a private method.

Example 2: Use __call to implement the "overload" action

<?php  
class Magic {  
  function __call($name,$arguments) {  
    if($name==&#39;foo&#39;) {  
  if(is_int($arguments[0])) $this->foo_for_int($arguments[0]);  
  if(is_string($arguments[0])) $this->foo_for_string($arguments[0]);  
    }  
  }   private function foo_for_int($x) {  
    print("oh an int!");  
  }   private function foo_for_string($x) {  
    print("oh a string!");  
  }  
} $x = new Magic();  
$x->foo(3);  
$x->foo("3");  
?>

Quoted from:

_call and ___callStatic are the default functions of the PHP class.

__call() In the context of an object, if the called method cannot be accessed, it will be triggered

__callStatic() In the context of a static object, if the called method cannot be accessed, It will be triggered

Instance:

<?php  
abstract class Obj  
{  
protected $property = array();  
  
abstract protected function show();  
  
public function __call($name,$value)  
{  
if(preg_match("/^set([a-z][a-z0-9]+)$/i",$name,$array))  
{  
$this->property[$array[1]] = $value[0];  
return;  
}  
elseif(preg_match("/^get([a-z][a-z0-9]+)$/i",$name,$array))  
{  
return $this->property[$array[1]];  
}  
else  
{  
exit("<br>;Bad function name &#39;$name&#39; ");  
}  
  
}  
}  
  
class User extends Obj  
{  
public function show()  
{  
print ("Username: ".$this->property[&#39;Username&#39;]."<br>;");  
//print ("Username: ".$this->getUsername()."<br>;");  
print ("Sex: ".$this->property[&#39;Sex&#39;]."<br>;");  
print ("Age: ".$this->property[&#39;Age&#39;]."<br>;");  
}  
}  
  
class Car extends Obj  
{  
public function show()  
{  
print ("Model: ".$this->property[&#39;Model&#39;]."<br>;");  
print ("Sum: ".$this->property[&#39;Number&#39;] * $this ->property[&#39;Price&#39;]."<br>;");  
}  
}  
  
$user = new User;  
$user ->setUsername("Anny");  
$user ->setSex("girl");  
$user ->setAge(20);  
$user ->show();  
  
print("<br>;<br>;");  
  
$car = new Car;  
$car ->setModel("BW600");  
$car ->setNumber(5);  
$car ->setPrice(40000);  
$car ->show();  
?>

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