In program development, if the calling method does not exist when invoking an object's internal method, the program will go wrong, and then the program exit cannot continue execution. So, when the program calls the method that does not exist inside the object, we are prompted to call the method and the parameters used do not exist, but the program can continue to execute, at this time we will use the method called when the non-existent method "__call ()".
<? PHP // This is a test class with no properties or methods. class test{} // produces an object of the test class $test New Test (); // methods that do not exist in the calling object $test->demo ("One", "one", "one", "three"); // The program will not execute here Echo "This is a test<br>";? >
The above example has the following error, the program can not continue execution;
Fatal error: Call to undefined method Test::demo()
;
Here we add the "__call ()" method, this method has 2 parameters, the first parameter is called the non-existent method procedure, when the __call () method is called automatically, the method name of the non-existent method is passed to the first parameter, the second parameter is to take the method of the multiple parameters to The form of an array is passed in .
<?PHP//This is a test class with no properties or methods.classtest{//methods that are called automatically when an existing method is called, the first parameter is the method name, the second argument is the array parameter function__call ($function _name,$args) { Print"The function you are calling:$function _name(Parameter: "; Print_r($args); Echo") does not exist! <br>"; }}//produces an object of the test class$test=NewTest ();//methods that do not exist in the calling object$test->demo ("One", "one", "one", "three"));//the program will not exit can be executed hereEcho"This is a test<br>";?>
The above example outputs the result:
the function You call: Demo (parameter: Array ([0] = + one [1] = [2] = three)) does not exist!
This is a test
PHP Object-oriented (OOP): __call () Handling Call errors