testinterface.java

介绍了java的一些应用

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package testinterface;

/**
 *
 * @author liuwei
 */
interface Addtion{public void add(double a,double b);}
interface Subtraction{public void minus(double a,double b);}
abstract class calcula{
    abstract public void multiply(double a,double b);
    abstract public void division(double a,double b);
} 
class interfaceca extends calcula
        implements Addtion,Subtraction{
    public void multiply(double a, double b) {
        System.out.println(a+"*"+b+"="+(a*b));
    }

    public void add(double a, double b) {
        System.out.println(a+"+"+b+"="+(a+b));
    }

    public void minus(double a, double b) {
        System.out.println(a+"-"+b+"="+(a-b));
    }

    public void division(double a, double b) {
        if(b!=0)
            System.out.println(a+"/"+b+"="+(a/b));
        else
            System.out.println("Error"); 
    }
}
public class TestInterface {
public static void main(String[] args){
    interfaceca cal=new interfaceca();
    cal.add(5.2, 6.3);
    cal.division(3.6,0);
    cal.minus(6.8, 522.1);
    cal.multiply(55.3,3.1);
}
}