Java关于方法的案例(购买机票，随机生成验证码)

 private  static double purchase(String kind, int month, double price){
        if(month>=5&&month<=10){
           switch (kind){
               case "经济舱": price*=0.9;break;
               case "头等舱": price*=0.85;break;
           }
        }
        else{
            switch (kind){
                case "经济舱": price*=0.7;break;
                case  "头等舱": price*=0.65;break;
            }
        }
        return  price;
    }

随机生成验证码：

  

private  static  String node(int n){
        String node="";
        Random r=new Random();
        for(int i=0;i