正文
初学java之接口基础
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/*
长城牌电视机
联想奔月5008PC机
*/ package st;
//接口回调实例
interface ShowMessage
{
void 显示商标 (String s);
}
class TV implements ShowMessage
{
public void 显示商标(String s)
{
System.out.println(s);
}
}
class PC implements ShowMessage
{
public void 显示商标 (String s)
{
System.out.println(s);
}
}
public class example_1
{
public static void main(String args[])
{
ShowMessage sm; //声明接口变量
sm=new TV(); //接口变量中存放对象的引用
sm.显示商标("长城牌电视机"); //接口回调
sm=new PC();
sm.显示商标("联想奔月5008PC机");
}
}
接口回调
/*
* 对于接口理解的一个列子
* 详情请关注龚细军（Gxjun）的博客
* */
package st; abstract class Motorvehicles
{
abstract void brake();
}
// 接口1
interface ControlTemperature
{
void ControlAirTemperature();
}
//接口2
interface MonenyFare
{
void Charge();
}
class Bus extends Motorvehicles implements MonenyFare
{
void brake()
{
System.out.println("公交车来啦！,嘟嘟");
}
public void Charge()
{
System.out.println("公交车收费为5毛");
}
}
class taxi extends Motorvehicles implements MonenyFare , ControlTemperature
{ void brake()
{
System.out.println("taxi来啦！,嘟嘟");
}
public void Charge()
{
System.out.println("taxi收费为5毛");
}
public void ControlAirTemperature()
{
System.out.println("taxi执行温度控制开关！");
}
}
class Cinema implements MonenyFare , ControlTemperature
{
public void Charge()
{
System.out.println("电影院收费为5毛");
}
public void ControlAirTemperature()
{
System.out.println("电影院执行温度控制开关！");
}
}
public class example_1 {
public static void main(String args[])
{
Bus myBus = new Bus();
taxi mytaxi = new taxi();
Cinema mycinema = new Cinema();
myBus.brake();
myBus.Charge();
mytaxi.brake();
mytaxi.Charge();
mytaxi.ControlAirTemperature();
mycinema.Charge();
mycinema.ControlAirTemperature();
}
}
/*
公交车来啦！,嘟嘟
公交车收费为5毛
taxi来啦！,嘟嘟
taxi收费为5毛
taxi执行温度控制开关！
电影院收费为5毛
电影院执行温度控制开关！
*/
接口与多态：
/*
11.23 22.78
a和b的算术平均值为：17.005000000000003
a和b的几何平均值为:15.99435525427643 */ package st ;
import java.util.Scanner;
interface c_average
{
public double average(double a, double b);
}
// 求算术平均值
class A implements c_average
{
public double average(double a , double b)
{
return (a+b)/2;
}
}
class B implements c_average
{
public double average(double a,double b)
{
return Math.sqrt(a*b);
}
}
public class example_1
{
public static void main(String args[])
{
Scanner reader=new Scanner(System.in);
double a,b;
a=reader.nextDouble();
b=reader.nextDouble();
A mya = new A();
System.out.println("a和b的算术平均值为："+mya.average(a, b));
B myb=new B();
System.out.println("a和b的几何平均值为:"+myb.average(a,b));
}
}
接口与多态
