Java4android (basic syntax for interfaces)

What is an interface? Defines an interface, which defines the criteria for calling an object

Basic syntax for the interface:

1. Use interface definition;

2. The methods in the interface are abstract methods;

3. The methods in the interface are public permissions

Basic syntax for Interfaces (ii):

1. Implement the interface using the Implements keyword

2. A class can implement multiple interfaces

3. A single interface can inherit multiple interfaces

Example:

Interface usb{// defines the interface public    void  read ();      Public void write ();}

Interface wifi{// defines the WiFi interface public    void  open ();          Public void close ();}

classPhoneImplementsusb,wifi{//implements implementation of Usbphone USB interface//implement all abstract methods in an interface     Public voidRead () {System.out.print ("Read"); }         Public voidwrite () {System.out.print ("Write"); }         Public voidOpen () {System.out.print ("Wifi Open"); }         Public voidClose () {System.out.print ("Wifi Close"); }}

class test{    publicstaticvoid  main (String args[]) {        new Phone ();         = Phone; // Upward Transformation         usb.read ();        Usb.write ();                 = Phone; // Upward Transformation         Wifi.open ();        Wifi.close ();     }}

An interface can inherit multiple interface examples:

Interface a{    void  Funa ();}

Interface b{    void  Funb ();}

Interface extends a,b{//C does not implement A/b interface, but inherits A, B. So c inside there are all methods of A, B, C interface,// when there is a class to implement the C interface, it is necessary to replicate A, B, c all methods    void  FunC ();}