第四次上机

class Cost{
    private double lastCost;
    private double thisCost;
    Cost() {
    }
    Elc(double lastCost,double thisCost) {
        this.lastCost=lastCost;
        this.thisCost=thisCost;
    }
    double getlastCost() {
        return this.lastCost;
    }
    double getthisCost() {
        return this.thisCost;
    }
    void setlastCost(double lastCost) {
        this.lastCost=lastCost;
    }
    void setthisCost(double thismElc) {
        this.thisCost=thisCost;
    }
    void showCost() {
        System.out.println("上月电表读数为:"+this.lastCost);
        System.out.println("本月电表读数为:"+this.thisCost);
    }
}
public class CostTest {
    public static void main(String[] args) {
        Cost a=new Cost();
        a.setlastCost(1000);
        a.setthisCost(1200);
        a.showCost();
        System.out.println("本月电费为:"+(a.getthisCost()-a.getlastCost())*1.2);
        Cost b=new Cost(1200,1450);
        b.setthisCost(1500);
        b.showCost();
        System.out.println("本月电费为:"+(b.getthisCost()-b.getlastCost())*1.2);
    }

}