Question

我正在尝试通过输入字母A，B，C ||来要求用户选择包裹。 a，b，c

我陷入困境，我们将不胜感激！谢谢！

public class AssignmentFive {

    public static void main(String[] args) {

        String A = "You chose package A";
        String B = "You chose package B";
        String C = "You chose package C";

        System.out.println ("Package A: For $9.95 per month, 10 hours of access is provided. Additional hours are $2.00 per hour.");
        System.out.println("Package B: For $13.95 per month, 20 hours of access is provided. Additional hours are $1.00 per hour");
        System.out.println("Package C: For $19.95 per month, unlimited access is provided");

        System.out.println();

        System.out.println("Please enter the letter of the package you want");

        Scanner value = new Scanner(System.in);
        System.out.println(value.nextLine());

        if(userinput) {
            System.out.println(B);
        }        

    }
}

线程“主”中的异常java.lang.Error：未解决的编译问题：无法将userinput解析为变量 Assignments.AssignmentFive.main（AssignmentFive.java:24）

Answer 1

这将起作用。

public class Main {

    public static void main(String[] args) {
        String A = "You chose package A";
        String B = "You chose package B";
        String C = "You chose package C";

        System.out.println ("Package A: For $9.95 per month, 10 hours of access is provided. Additional hours are $2.00 per hour.");
        System.out.println("Package B: For $13.95 per month, 20 hours of access is provided. Additional hours are $1.00 per hour");
        System.out.println("Package C: For $19.95 per month, unlimited access is provided");

        System.out.println();

        System.out.println("Please enter the letter of the package you want");

        Scanner value = new Scanner(System.in);
        String userinput = value.nextLine().toUpperCase();

        if((userinput.equals("A")))
            System.out.println(A);
        else if ((userinput.equals("B")))
            System.out.println(B);
        else if ((userinput.equals("C")))
            System.out.println(C);
        }
  }

Answer 2

您需要按照异常说明声明userInput变量。这种特殊的异常是编译时异常，您需要在运行程序之前解决它。

此外，您还需要修改if条件，因为它取决于您如何定义userInput变量。目前，它是布尔变量。如果将userInput定义为字符串，则必须使用equals方法来验证用户输入。

字符串扫描仪

2 个答案: