创建类

package duix;

public class Shu {

    //书的种类
    public String Shuzl;
    
    //书的名字
    public String Shumz;
    
    //某本书的限定额
    int Shuxde;
    
    //当前本书的数量
    int Dangqsl;
    
    public Shu(String shuzl,String shumz,int shuxde)
    {
        this.Shuzl = shuzl;
        this.Shumz = shumz;
        this.Shuxde = shuxde;
    }
    
    //增添书本
    public void Zengjia(int Zengsl)
    {
        //实际增添书本的数量
        int sjzsl = Shuxde - Dangqsl;
        
        Dangqsl += Zengsl;
        
        //本书已达限定额
        if (Dangqsl >= Shuxde)
        {
            System.out.println("本书已达限定额，请停止增添");
            
            Dangqsl = Shuxde;
            
        }
        else
        {
            sjzsl = Zengsl;
        }

        System.out.println("增添书量 =" + Zengsl + ",当前本书数量 =" + Dangqsl);
    }
    //每本书单价
    public int Danjia = 50; 
    
    //出售书本
    public void Chushou(int Shengyusl)
    {
        int Shouchusl = Shuxde - Shengyusl;
        
        Dangqsl -= Shouchusl;
        
        System.out.println("剩余书本数量 =" + Shengyusl + "当前书本数量 =" + Dangqsl);
        
        int xiaoshouzj = Danjia * Shengyusl;
        
        System.out.println("销售总价 =" + xiaoshouzj);
    }
    
    
}







package duix;

public class shutest {

    public static void main(String[] args){
        
        Shu shu = new Shu("小说","红楼梦",40);
        
        shu.Dangqsl = 10;
        
        shu.Zengjia(20);
        
        shu.Danjia= 50;
        
        shu.Chushou(20);
        
        
        //书
        Shu shu1 = new Shu("","",30);
        
        shu1.Danjia = 50;