Summary and use examples of magic methods in PHP _php tutorial

Summary and usage examples of magic methods in PHP

This article mainly introduces the Magic method in PHP summary and use examples, the Magic method is the PHP object-oriented features, they are triggered in a particular case, are to start with a double underscore, you can interpret them as hooks, the need for friends can refer to the next

The Magic method is a unique feature of PHP object-oriented. They are triggered under certain circumstances, all starting with a double underscore, you can interpret them as hooks, and the pattern method makes it easy to implement PHP object-oriented overloading (overloading, which dynamically creates class properties and methods). Many of the magic methods are still paired, and the following list shows all the schema methods in PHP currently.

1.__construct,__destruct

__constuct is called when the object is built;

__destruct explicitly destroys the object or is called at the end of the script;

2.__get,__set

__set called when an attribute assignment is not accessible or does not exist

__get is called when read is not accessible or there is no property

3.__isset,__unset

__isset called when isset () or empty () is called on an inaccessible or nonexistent property

__unset called when an unreachable or nonexistent property is unset

4.__call,__callstatic

Called when __call calls a method that is not accessible or does not exist

Called when __callstatic calls a static method that is not accessible or does not exist

5.__sleep,__wakeup

__sleep is called when using serialize, which is useful when you don't need to save all the data for a large object

__wakeup is called when using unserialize, and can be used for initialization of objects

6.__clone

Called when the object clone is being used to adjust the cloning behavior of the object

7.__tostring

Called when a class is converted to a string

8.__invoke

Called when an object is called in a functional manner

9.__set_state

This static method is called when the Var_export () export class is called. Use the return value of __set_state as the return value of Var_export.

10.__debuginfo

Called when a var_dump () print object is called (when you do not want to print all properties) for the PHP5.6 version

Examples of using the PHP magic method are:

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Class Magic { Public $var = ' Test '; Constructor that is called when the object is created Public Function __construct () { Echo ' __construct called '. Php_eol; } A reference to an object is deleted, the object is destroyed, a call to exit () is called, and the script is closed Public Function __destruct () { Echo ' __destruct called '. Php_eol; } Called when an attribute assignment is not accessible or does not exist Public Function __set ($name, $value) { echo $name. '-' $value; Echo ' __set called '. Php_eol; } Called when the read is not accessible or the property is not present Public Function __get ($name) { Echo $name; Echo ' __get called '. Php_eol; } Called when a method is called that is not accessible or does not exist Public Function __call ($name, $arguments) { Echo $name. '-' . Implode (', ', $arguments); Echo ' __call called '. Php_eol; } Called when a static method is called that is not accessible or does not exist public static function __callstatic ($name, $arguments) { Echo $name. '-' . Implode (', ', $arguments); Echo ' __callstatic called '. Php_eol; } Called when isset () or empty () is called for an unreachable or nonexistent property Public Function __isset ($name) { Echo $name; Echo ' __isset called '. Php_eol; return true; } Called when an unset property is not accessible or not present Public Function __unset ($name) { Echo $name; Echo ' __unset called '. Php_eol; } Serialize is called when you don't need to save all the data for a large object. Public Function __sleep () { Echo ' __sleep called '. Php_eol; Return Array (' var1111111111 '); } Unserialize is called when it is used to initialize objects. Public Function __wakeup () { Echo ' __wakeup called '. Php_eol; $this->var = ' test after wakeup '; } Called when a class is converted to a string Public Function __tostring () { Return ' __tostring called '. Php_eol; } Called when the object clone is being used to adjust the cloning behavior of the object Public Function __clone () { Echo ' __clone called '. Php_eol; } Called when an object is called in a functional manner Public Function __invoke () { Echo ' __invoke called '. Php_eol; } This static method is called when the Var_export () export class is called. Use the return value of __set_state as the return value of Var_export. public static function __set_state ($arr) { Return ' __set_state called '. Php_eol; } Called when a var_dump () print object is called (when you do not want to print all properties) for the PHP5.6 version Public Function __debuginfo ($arr) { Echo ' __debuginfo called '. Php_eol; Return Array ( ' var ' = ' Test fro __debuginfo ' ); } } $m = new Magic (); __construct () is called $m->not_exist_property = test; __set () is called echo $m->not_exist_property;//__get () is called $m->abc (a); __call () is called Echo isset ($m->not_exist_property); __isset () is called and returns a bool value unset ($m->not_exist_property); __unset () is called echo $tmp = serialize ($m); __sleep () is called Unserialize ($TMP); __wakeup () is called $m 1 = clone $m; __clone () is invoked, the object is passed by default, and the Clone keyword is used to implement object replication $m (); __invoke () Eval (' $m 2 = '. Var_export ($m, True). ';' ); Var_dump ($m 2); Var_dump ($m); Last __destruct () is called /* Results: __construct called Not_exist_property-test__set called Not_exist_property__get called Abc-1,2,3__call called Not_exist_property__isset called 1not_exist_property__unset called __sleep called O:5: "Magic": 1:{s:13: "var1111111111"; N;} __wakeup called __destruct called __clone called __invoke called String ("__set_state called") " Class Magic#1 (1) { Public $var = = String (4) "Test" } __destruct called __destruct called */

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