PHP Object-oriented various concepts and usage example code detailed

This article mainly introduced the PHP object-oriented programming method, combined with the case form in detail the PHP object-oriented programming involved in the concept of classes, definitions, constructors, destructors, inheritance, overloading, interfaces, abstract classes and other concepts and use of skills, the need for friends can refer to the next

This paper analyzes the object-oriented programming method of PHP. Share to everyone for your reference, as follows:

PHP5 begins to support object-oriented, as shown in the following example:

<?phpclass classname{var $attr 1;  var $attr 2;  Public $attribute;  Const PI = 3.14;  constructor function construct ($param = ' default ') {echo "Constructor called with parameter $param <br/>";  }//destructor function destruct () {echo ' <br/>destruct ';  }//function Oper1 () {echo ' oper1<br/> ';    } function Oper2 ($param) {$this->attr1 = $param;  Echo $this->attr1;  } protected function Oper3 () {echo ' This is protected function<br/> ';  }//Disallow inheritance of final function Oper5 () {} function get ($name) {return $this, $name;  } function set ($name, $value) {$this, $name = $value;  }//static method, statically function double ($param) {return $param * $PARAM; }} $a = new classname (' first '), $b = new classname (' Second '); $c = new classname (); $c->oper2 ("Hello"); Echo ' <br/> ' echo $c->attr1;echo ' <br/><br/> '; Echo ' Per-class constant classname::P i-'. ClassName::P i;echo ' <br/> static method: ClassName::d ouble (3)-'. ClassName::d OubLe (3); Echo ' <br/> ';//implement Inherit echo ' implementation inheritance <br/> '; class B extends classname{function oper4 () {$this->oper3 ( );  The protected method can only be used in the} function Oper1 () {//Overload echo ' This is class B/' s oper1. <br/> ';  }} $d = new B ("forth"); $d->oper1 (); $d->oper4 ();//Interface interface displayable{function display (); function Show ();}  Class C implements displayable{function display () {echo ' This is the method of the corresponding interface. <br/> '; The function Show () {}} $e = new C (); $e->display (); Echo ' Checks if $e is an instance of C: '; Echo ($e instanceof C)?  ' Yes ': ' No ';//Clone the object $f = Clone $e; Echo ' <br/><br/> can use the Clone () method, which is invoked when using the Clone keyword;//abstract class Abstraction classes e{}//$f = new E ();  This will be an error, cannot instantiate abstract class//parameter overloading, polymorphic class f{public $a = 1;  Public $b = 2;  Public $c = 3;  function DisplayString ($elem) {echo ' <br/>string: '. $elem;  } function Displayint ($elem) {echo ' <br/>int: '. $elem;     }//Note parameter $p, which is passed in as an array, must use the subscript to access function call ($method, $p) {if ($method = = ' Display ') {if (is_string ($p [0])) {   $this->displaystring ($p [0]);      } else {$this->displayint ($p [0]); }}}} $g = new F (), $g->display (' abc ');//iterator, read all properties of the instance foreach ($g as $att) {echo ' <br/> '. $att;} Reflect Echo ' <br/> '; $class = new Reflectionclass (' F '); Echo ' <pre> '; echo $class; Echo ' </pre> ';? >