Functions as an interface: can be realized design and implementation separation, abstract common than N different types.
For example: aircraft, birds, balls, missiles, spacecraft ......
Inheritance: is -a relationship triangle is a geometric
Bird is a ball ? Does not hold
Interface : has -a between the phone has a camera function
The plane has a flying capability
Bird has a flying capability
Interface is a manifestation of the ability to
Acquaintance Interface
If a class all methods are abstract methods, then this class can be declared as an interface
public abstract class MyClass {
public abstract void show();
public abstract String fun();
public abstract int [] method();
}
The following code can be changed
public interface MyInterface {
void show();
String fun();
int [] method();
}
Definition of the interface: the use interface modification, a data type, data type reference
Interface definition :
public interface MyInterface {
void show();
}
What interface can contain?
(1) an abstract method
public abstract method
(2) non-abstract methods
/**JDK1.8新特性 ,必须使用default关键字*/
public default void method2(){
}
(3) Properties ( public static Final ) Constant , public static final can be omitted
public interface MyInterface {
String name="张三"; public static final String name2="张三"; }Note: Can contain constructors interface it? It is not allowed , because the interface is not a class
