PHP class and object interface definition Introduction and usage examples

Implementation of the interface

The <?php//interface keyword is used to define an interface interface icaneat{       //interface inside the method does not need to implement public       function eat ($food);} The Implements keyword is used when a class implements an interface class Human implements icaneat{       //Implements an interface and must provide a concrete implementation of the method in the interface public       function eat ($food) {       echo "Human eating". $food;    }? >

So, after the definition of this pass,

By instantiating an object

$peroson 1=new Human ();

$person 1->eat (' Apple ');

The result of the output is

Human eating apple

The <?php//interface keyword is used to define an interface interface icaneat{       //interface inside the method does not need to implement public       function eat ($food);} The Implements keyword is used when a class implements an interface class Human implements icaneat{       //Implements an interface and must provide a concrete implementation of the method in the interface public       function eat ($food) {       echo "Human eating". $food. " \ n ";    }} $person 1 = new Human (), $person 1->eat (' Apple ');//We can determine whether an object implements an interface Var_dump ($person 1 instanceof by instanceof keyword) Icaneat);//In the example above we can use this keyword to determine whether the Icaneat interface is implemented?>

Then the output should be

Human eating apple

Bool (True)

The <?php//interface keyword is used to define an interface interface icaneat{//interface methods do not need to implement public function eat ($food);} The Implements keyword is used for classes that implement an interface class Human implements icaneat{//implement an interface, you must provide a concrete implementation of the method in the interface public function eat ($food) {echo "Human Eating ". $food." \ n ";}} $person 1 = new Human (), $person 1->eat (' Apple ');//We can determine whether an object implements an interface Var_dump ($person 1 instanceof by instanceof keyword) Icaneat);//In the above example, we can use this keyword to determine whether the implementation of Icaneat this interface//class can inherit, then the interface can also be inherited interface Icansleep extends icaneat{public function sleep ();} When a class implements a Subinterface, the method defined by the parent interface also needs to be implemented in the class to specifically implement class Human1 implements icansleep{public function eat ($food) {} Public Function sleep () { }}?>