Java黑马程序员案例代码答案|Java基础黑马程序员教材案例4-5..图形的面积与周长计算程序、案例4-7经理与员工工资代码算法|java

一、 4-5图形的面积与周长计算程序

import java.util.Scanner; import java.math.*; public class areaCount {publicvoid menu () {System.out.println ("输入1计算圆的周长、面积"); System.out.println ("输入2计算长方形的周长、面积"); Scanner scanner = new Scanner (System.in); int choice = scanner.nextInt (); if (choice == 1) {yuan yuan = new yuan (); System.out.println ("输入圆的周长"); double r = scanner.nextDouble (); yuan.areaCount ( r); yuan.zhouchangCount (r); } else if (choice == 2) {changfangxing changfangxing = new changfangxing (); System.out.println ("依次输入长方形的长和宽"); doublelength=scanner.nextDouble (); double width=scanner.nextDouble (); changfangxing.areaCount (length,width); changfangxing.zhouchangCount (length,width); } } public static void main (String[] args) {areaCount areaCount=new areaCount (); areaCount.menu (); }abstract class graph {double area = 0; double zhouchang = 0; }class yuan extends graph {double r = 0; public void areaCount (double r) {area = 3.14 * (r * r); System.out.print ("面积是："); System.out.println (area); }public void zhouchangCount (double r) {zhouchang = 2 * 3.14 * r; System.out.print ("周长是："); System.out.println (zhouchang); } }class changfangxing extends graph {double length = 0; double width = 0; public void areaCount (double length,double width) {area = length * width; System.out.print ("面积是："); System.out.println (area); }public void zhouchangCount (double length,double width) {zhouchang = (length + width) * 2; System.out.print ("周长是："); System.out.println (zhouchang); } } }

二、案例4-7经理与员工工资代码

public class salary {public static void main (String[] args) {jingli guan=new jingli (); guan.salary=10000000; normal zjw=new normal (); zjw.salary=100000000; guan.work (); zjw.work (); System.out.println ("经理工资"+guan.salary); System.out.println ("普通员工工资"+zjw.salary); } } classPerson{String name; String address; int id; int salary; int age; publicvoid work(){} } class jingli extends Person{@Override publicvoidwork(){salary+=0.2*salary; }} class normal extends Person{@Override publicvoid work(){salary+=0.1*salary; }}