Question

此程序要求用户输入一个数字，然后从列表中返回详细信息。我该怎么做？

         do {
          Scanner in = new Scanner(System.in);             
            System.out.println("Enter Number <terminated by 1>");

             }  while (!input.equals("-1"));
                System.out.println("Session Over");

        } catch (Exception e) {   
            System.out.println(e);
        }
    }
}

输出：

Enter Number <terminated by 1>
123456
Person Number: 12

Answer 1

with open(myfilename, 'w') as csvfile: writer = csv.DictWriter(csvfile) for a,b,c in zip(zmin_limits,zmax_limits,mlim_limits): info = id_match(data_zcosmo_lastz,data_zphot_lastz,a,b,c) writer.writerow(info)是比较两个整数值的正确方法。

Answer 2

在java中，当变量在循环内部时，你无法在do-while循环中测试变量：

part1 &
part2 &
part3 &
part4 &
wait

不会编译。

此外，do { int i = 10; } while (i > 5);没有int input;方法，因为equals类型是原始的。

Answer 3

首先从循环中删除扫描仪初始化并将其放入try块中，如Pshemo指出的那样。

try {
    Scanner in = new Scanner(System.in);
do {
    yada yada yada
}

然后尝试在你的while循环中包含你的否定，如下所示：

while (!(input.equals("-1")));

Answer 4

专业提示：使用IDE。

您的代码错误至少有两个原因：

您的int input已在do块中定义，因此在关闭后无法显示
您在基本类型

.equals

按如下方式更正您的代码：

public class Client {

    public static void main(String[] arg) {
        Client c = new Client();
        c.run();
    }

    private void run() {
        StudentData p = new StudentData();
        List<StudentDetailsType> personDetailsList = (List<StudentDetailsType>) p.getList();


        // input defined outside the do block so it is visible in while clause
        int input;
        // declare the scanner just one time here, so it will be closed automatically as the try/catch block ends
        try(Scanner in = new Scanner(System.in)) {
            do {
                System.out.println("Enter 6 digit Student Number <terminated by -1>");
                input = in.nextInt();
                for (StudentDetailsType q : personDetailsList) {

                    if (q.getStudentNumber() == input) {
                        System.out.println("Student Number: " + q.getStudentNumber() + "\n" + "Student Name: "
                                + q.getStudentName() + "\n" + "Result 1: " + q.getResult1() + "\n" + "Result 2: "
                                + q.getResult2() + "\n" + "Result 3: " + q.getResult3());
                        break;
                    }
                }
            } while (input != -1); // use an int comparison (!= that means not equals)

            System.out.println("Session Over");

        } catch (Exception e) {
            System.out.println(e);
        }
    }
}

java在终止时做

4 个答案: