interface SoundEmitter {
// ...
}
interface SoundEmitter {
string emitSound(); //仅声明
}
interface I {
int func(int i)
in {
} out { //可用进出来保证
}
}
class Violin : SoundEmitter {
string emitSound() {
return "sss";
}
}
class Bell : SoundEmitter {
string emitSound() {
return "ding";
}
}
void useSoundEmittingObject(SoundEmitter object) {
//接口实现多态
writeln(object.emitSound());
}
interface CommunicationDevice {
void talk(string message);
string listen();
}//多个接口
class Phone : SoundEmitter, CommunicationDevice {
// ...
}
class Phone : SoundEmitter, CommunicationDevice {
string emitSound() { // for SoundEmitter
return "rrring";
}
void talk(string message) { // for CommunicationDevice
// ... put the message on the line ...
}
string listen() { // for CommunicationDevice
string soundOnTheLine;
// 处理
return soundOnTheLine;
}
}
class Clock {
// ... clock implementation ...
}
class AlarmClock : Clock, SoundEmitter {
//可继承一个类,多个接口
string emitSound() {
return "beep";
}
}
static size_t makeNewId() {
immutable newId = nextId;
++nextId;
return newId;
}
//静态成员,只能包含静态变量.不能含`成员变量`,没有`本`.
final
表最终函数,表最终类(叶类
)