在进行用户输入时打印格式

Question

我有一个大学作业,我需要打印出硬件商店出售的商品,从用户那里获取输入,对该输入执行一些计算,然后打印出发票.

我已经能够成功打印出硬件商店销售的商品,但是遇到while了输入的循环问题.

程序要求用户输入CODE,然后询问相应的QUANTITY.这在循环的第一次迭代中工作正常,但在第二次迭代时,用户提示"CODE:"和"QUANTITY:"出现在同一行,尽管我println在提示用户时使用了它.

我非常感谢适合新编程人员的详细回复.

这是代码:

 import java.util.Scanner;

 class HardwareStore {


    public static void main(String[] args) {

        Scanner in = new Scanner(System.in);


        System.out.println("WELCOME TO THE HARDWARE STORE!");
        System.out.println("----------------------------------------------------------------------");


        String sticky = "G22";
        String keyring = "K13";
        String screwy = "S21";
        String padlock = "I30";


        int stickyprice = 10989;
        int keyringprice = 5655;
        int screwyprice = 1099;
        int padlockprice = 4005;


        System.out.println("CODE\t\tDESCRIPTION\t\t\t\t\tPRICE");
        System.out.println("----\t\t-----------\t\t\t\t\t-----");

        System.out.println(sticky + "\t\tSTICKY Construction Glue, Heavy Duty, \n\t\t7oz, 12 Pack \t\t\t\t\t$" + stickyprice);
        System.out.println(keyring + "\t\tCAR-LO Key Ring, Quick Release, \n\t\t1 Pack\t\t\t\t\t\t$ " + keyringprice);
        System.out.println(screwy + "\t\t!GREAT DEAL! SCREW-DUP Screwy Screws, \n\t\tDry Wall Screws, 3 in. Long, 50 Pack\t\t$ " + screwyprice);
        System.out.println(padlock + "\t\tLET-IT-RAIN, Weather Proof Padlock, \n\t\tPortable, One Push Functionality\t\t$ " + padlockprice);
        System.out.println("----------------------------------------------------------------------");


        int i = 10000; 
        String [] usercode = new String[i]; 
        int [] userquantity = new int[i];


        System.out.println("PLEASE ENTER YOUR ORDER:");


        while (true) {
            System.out.println("CODE: (X to terminate)");
            usercode[i] = in.nextLine();

            if (usercode[i].equalsIgnoreCase("x")) {
                break;
            }

            System.out.println("QUANTITY: ");
            userquantity[i] = in.nextInt();
        } 
    }
}

Answer 1

当你进入QUANTITY你按下回车.该newline字符未被使用in.nextInt();,它保留在扫描仪缓冲区中,直到您in.nextLine()再次滚动.

在那一刻in.nextLine()读取,直到找到换行符,恰好是缓冲区中的下一个.所以它QUANTITY再次直接跳过.