calculator.java

介绍了java的一些应用

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package Calculator;

/**
 *
 * @author liuwei
 */
class fathercalcul{
    double a,b,c;
 /*   fathercalcul(double a1,double b1){
        a=a1;b=b1;
    }*/
    void setnum(double a1,double b1)   {
        a=a1;b=b1;
    }
    void add(){
        System.out.println("call father class's add function");
       c=a+b;
    }
    void minus(){
        c=a-b;
    }
    void multiply(){
        c=a*b;
    }
    void divide(){
        if(b!=0)c=a/b;
        else 
            System.out.println("error");
    }
    void showanswer(){
        System.out.println("call father class's function,the answer is"+c);
    }
}
class soncalcul extends fathercalcul{
    //soncalcul(){}
    void add(){
         System.out.println("call son class's add function");
        c=a+b;
    }
     void showanswer(){
         super.showanswer();
        System.out.println("call son class's function,the answer is"+c);
    }
    public static void main(String[] args){
        fathercalcul fc=new fathercalcul();
        soncalcul sc=new soncalcul();
        fc.setnum(5.2,6.3);
        sc.setnum(5.0,7.2);
        fc.add();
        fc.showanswer();
        sc.add();
        sc.showanswer();
    }
}