Summary of magic methods for php surface objects

What are PHP object-oriented magic methods and how each magic method works? please write a Test class and run

 Non-empty string, non-zero, true, array with units will be converted to true; 0, "0", empty * string, NULL, an array without cells will be converted to false). * parameter: $ name indicates the name of the member variable to be detected. the passing of this parameter is automatically completed by PHP. * return value: type (uncertain) note that this method can be set to private (the constructor should not be set to private). when isset () is used () the function can directly detect * public member variables. if The _ isset () method is not used, direct detection of private members will result in inaccurate results, that is, isset () * always returns false; * _ unset ($ name) * function: This method is automatically called When unset ($ name) is used to cancel a private member variable; * parameter: $ name indicates the name of the member variable to be revoked. this parameter is automatically passed by PHP. * return value: the value cannot be returned. an error occurs when the value is forcibly returned, when unset () function is used to revoke a Public * Member variable, it can be directly revoked. if The _ unset () method is not used * _ ToString () * function: PHP automatically calls this method when trying to output an object type variable to a certain extent. * parameter: no parameter, if an error is reported, * return value: string (this method must return a string); * _ clone () * function: PHP automatically calls this method when cloning an object with the clone keyword to add its own properties and methods to the cloned object. * parameter: no parameter is required; * return value: no return value. * _ call ($ name, $ argument) * function: This method is automatically called when a program attempts to call a nonexistent member method. * parameter: PHP will automatically pass the called non-existing method name to $ name, and the parameters in the non-existing method will be integrated into an array and passed to * $ argument; * return value: no return value; * _ sleep (): when using the serialize () function, if the instantiated object contains the _ sleep () method, the _ sleep () method is executed first. You can clear the * object and return an array of all the variables in the object. The _ sleep () method is used to disable similar * aftercare * parameters such as database connections that an object may have: no parameters need to be passed * return value: Array type (Array) * _ wakeup () * function of all variables in this object: Use the unserialize () function to restore an object serialized by the serialize () function, __wakeup () the method is to recover * lost database connections and related work * parameters in serialization: no parameter needs to be passed * return value: ------------------------ * _ set_state ($ arr) * function: you can use var_export () to obtain the static method _ set_state () of the handler class. this method must be static and must return an object * parameter: $ arr as an array * returned value: as an object ** _ autoload ($ class_name) * function: automatically searches for and imports the class required for instantiation in the specified path * parameter: $ class_name indicates the class name * returned value: * _ call Static ($ name, $ argument) * function: This method is automatically called when a program attempts to call an undefined or invisible member method in a Static method. * parameter: PHP will automatically pass the called non-existing method name to $ name, and the parameters in the non-existing method will be integrated into an array and passed to $ argument; * return value: no return value; * Note: PHP5.3 and later versions support this magic method * Note: __classstatic () must be declared as public and static; otherwise, a warning error * _ invoke ($ x, $ y ,...) * function: when an object is called by calling a function, the __invoke method is automatically called. * Parameter: any number of parameters passed when an object is called using a function call method * return value: uncertain * Note: PHP5.3 and later versions support this magic method **/class XuDianYang {public $ sex; public $ age; private $ girlfriend = 'XX'; public function _ construct ($ sex, $ age) {$ this-> sex = $ sex; $ this-> age = $ age;} public function _ get ($ name) {echo _ class __. "::". $ name. "nonexistent or invisible";} public function _ set ($ name, $ value) {echo _ class __. "::". $ name. "Assignment failed because it is not present or invisible";} public function _ isset ($ name) {if (isset ($ this-> $ name) {echo 1 ;} else {echo 0 ;}} public function _ unset ($ name) {unset ($ this-> $ name);} public function _ toString () {return _ class __;} public function _ clone () {$ this-> sex = 'femal';} public function _ call ($ name, $ argument) {echo "method ". _ class __. "::". $ name. "does not exist";} public function _ sleep () {echo "I'm sleeping"; foreach ($ this as $ key => $ value) {$ arr [] = $ key;} return $ arr;} public function _ wakeup () {echo "I wake up";} public function _ set_state ($ arr) {$ obj = new CheShi (); $ obj-> var1 = $ arr ['sex']; $ obj-> var2 = $ arr ['age']; return $ obj ;}} function _ autoload ($ name) {$ class_path = ". /"; include_once ($ class_path. $ name. ". class. php ") ;}$ xudianyang = new XuDianYang (" male ", 21); echo"
"; // Normal access to sex properties echo $ xudianyang-> sex; echo"
"; // Because the weight attribute does not exist, the _ get () method echo $ xudianyang-> weight; echo" is automatically called"
"; // Because it is invisible (private), The _ get () method $ xudianyang-> girlfriend; echo" is automatically called"
"; // The value assignment fails because it does not exist. The _ set () method $ xudianyang-> shengao =" 172 "; echo" is automatically called"
"; // Check whether the sex property exists. because sex public directly detects var_dump (isset ($ xudianyang-> sex); echo"
"; // Checks whether girlfriend exists. because girlfriend is private, the _ isset () method isset ($ xudianyang-> girlfriend) is automatically called. echo"
"; // Undo girlfriend. because girlfriend is private, the _ unset () method is automatically called. // unset ($ xudianyang-> girlfriend); isset ($ xudianyang-> girlfriend ); echo"
"; // Directly output an object and automatically call the _ toString () method echo $ xudianyang; echo"
"; $ Xu = clone $ xudianyang; echo $ xu-> sex; echo"
"; // Because the call does not exist, the _ call () method $ xudianyang-> walk (); echo" is automatically called"
"; // Serialize the object, automatically call the _ sleep () method $ a = serialize ($ xudianyang); echo"
"; Echo" the serialization result is: ". $ a; // deserialization object, automatically calling the _ wakeup () method echo"
"; $ B = unserialize ($ a); // deserialization result echo $ B-> sex; echo"
"; Eval ('$ c ='. var_export ($ xudianyang, true)."; "); echo $ c-> var1;?> CheShi. class. php