包含抽象方法的枚举类

//注：jdk版本一定要在1.5以上

package student;
/**
* 包含抽象方法的枚举类
* 枚举值包括：plus、minus、times、divide
* plus：加
* minus：减
* times：乘
* divide：除
* 为枚举类定义一个抽象的方法来实现不同的枚举值
*/
public enum abstractenum
{
plus
{
public double eval(double x,double y)
{
return x+y;
}
},
minus
{
public double eval(double x,double y)
{
return x-y;
}
},
times
{
public double eval(double x,double y)
{
return x*
y;
}
},
divide
{
public double eval(double x,double y)
{
return x/y;
}
};
public abstract double eval(double x,double y);
public static void
main(String[] args) {
System.out.println(abstractenum.plus.eval(5,6));
System.out.println(abstractenum.minus.eval(5,6));
System.out.println(abstractenum.times.eval(9,6));
System.out.println(abstractenum.divide.eval(5,6));

}

}