package ming;
enum Operation {
PLUS {
public double eval(double x, double y) {
return x + y;
}
},
MINS {
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) {
if (y == 0) {
return -1;
}
return x / y;
}
};
//为枚举类定义抽象方法，具体由枚举值提供实现
public abstract double eval(double x, double y);
}
public class OperationTest {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println(Operation.PLUS.eval(1, 2));
System.out.println(Operation.DIVIDE.eval(1, 0));
}
}
