Javase Review Diary: interface

/* * interface * Reference data type: * Class, interface, array; * * Interface is a reference data type that can be As a special class, its existence is designed to solve the problem of weak functionality caused by multiple inheritance, a class can have only one parent class, but this class can implement multiple interfaces; * * Interfaces can also be considered as classes with only abstract methods, that is, all methods of an interface must be implemented; * The keyword of the interface declaration is interface, instead of class, and the inheritance keyword extends of the common class becomes the implements (implementation); * But its function is the same as the ordinary class, but only to distinguish; * * * 1 defines the syntax of the interface: * [modifier list] Interface interface Name {} * 2 interface content: * Can only be constant (public static final constant name) and abstract party       Method * 3 Abstract methods do not need to be modified, the default is public (do not need to add) * 4 interface can be regarded as a special abstract class, is completely abstract, there is no ordinary method * 5 interface is no construction method, that is, the interface can not be instantiated * 61 classes can implement multiple interfaces, but only one class * 71 non-abstract class implementation interface, you need to implement all the methods in the interface (override/overwrite) * That abstract class implementation interface? * Abstract class implementation interface, can implement any: 0~n * 8 interface between: * can inherit, not only that, the interface can also inherit more, compared to the class can only inherit * * Constant and static data difference: * All is initialized at the time the class is loaded, but static data can be assigned multiple times * constants: Generally, the public static final decoration must be used to declare constants in the interface, which can be omitted; * Naming mode: uppercase and lowercase with an underscore in the form of name; * Note: The above section needs to distinguish between interface and interface "Inheritance", Class and interface "Implementation", Class and Class "inheritance"; */ Public classjavase{ Public Static voidMain (string[] args) {f f=NewF ();        F.M1 ();        F.M2 ();        F.M3 ();    F.M4 (); }}Interfacea{//interface A     Public voidM1 ();}Interfaceb{//Interface B     Public voidm2 ();}Interfacec{//Interface C    voidM3 ();//The public of the method in the interface can be omitted;}InterfaceD extends a,b,c{//multiple inheritance of interfaces    voidM4 ();}classMyClass Implements b,c{//implementation of common class-to-interface     Public voidm2 () {System. out. println ("m2 () method for overwrite B interface" ); }     Public voidm3 () {System. out. println ("m3 () method for overwrite C interface" ); }}Abstract classE Implements d{//implementation of an abstract class-to-interface     Public StaticFinalintA =Ten;//how constants are declared    CharE'in';  Public voidM1 () {} Public voidm2 () {} Public voidm3 () {} Public voidM4 () {}}classF extends e{//need to overwrite all the methods in E     Public voidM1 () {System. out. println ("Overwrite M1 () method" ); }     Public voidm2 () {System. out. println ("overwrite m2 () method" ); }     Public voidm3 () {System. out. println ("overwrite m3 () method" ); }     Public voidM4 () {System. out. println ("overwrite the M4 () method in D" ); }}

Javase Review Diary: interface