扫描仪不会停止获取输入

Question

好吧，非常菜鸟的问题。我正在制作一个CLI应用程序，使用户可以设计调查。他们首先输入问题，然后输入选择的数量和选择。我正在使用扫描仪来获取输入，由于某种原因，它允许用户输入大多数内容，但不能输入问题的内容。下面的代码段。

String title = "";
Question[] questions;
int noOfQuestions = 0;
int[] noOfChoices;
Scanner entry = new Scanner(System.in);
System.out.println("Please enter the title of the survey: ");
title = entry.nextLine();
System.out.println("Please enter the number of questions: ");
noOfQuestions = entry.nextInt();
noOfChoices = new int[noOfQuestions];
questions = new Question[noOfQuestions];
for (int i = 0; i < noOfQuestions; i++) {
    questions[i] = new Question();
}
for (int i = 0; i < noOfQuestions; i++) {

    System.out.println("Please enter the text of question " + (i + 1) + ": ");
    questions[i].questionContent = entry.nextLine();
    System.out.println("Please enter the number of choices for question " + (i + 1) + ": ");
    questions[i].choices = new String[entry.nextInt()];
    for (int j = 0; j < questions[i].choices.length; j++) {
        System.out.println("Please enter choice " + (j + 1) + " for question " + (i + 1) + ": ");
        questions[i].choices[j] = entry.nextLine(); 

    }
}

谢谢 ：）

Answer 1

我询问您是否noOfQuestions从扫描仪读取数据的原因是因为Scanner.nextInt()它不占用定界符（例如，新行）。

这意味着下次调用时nextLine()，您只会从前一个字符串中得到一个空字符串readInt()。

75\nQuestion 1: What is the square route of pie?
^ position before nextInt()

75\nQuestion 1: What is the square route of pie?
  ^ position after nextInt()

75\nQuestion 1: What is the square route of pie?
    ^ position after nextLine()

我的建议是始终按行逐行阅读nextLine()，然后使用解析Integer.parseInt()。

如果那是您选择的路线，那么根本不需要扫描仪。您可以只接受BufferedReader。