variable.nextInt() 在 Java 程序中不工作

Question

 Scanner input = new Scanner(System.in);
    System.out.println("Please enter the name of the first subject");
    String A = input.nextLine();
    System.out.println("Please enter marks in subject " + A );
    float a = input.nextFloat();
    **System.out.println("Please enter the name of the second subject");
    String B = input.nextLine();
    System.out.println("Please enter the marks of the subject "+ B );**
    float b = input.nextFloat();
    System.out.println("Please enter the name of the last subject");
    String C = input.nextLine();

在此代码中，我希望该程序在获取第一个主题标记的值后询问第二个主题的名称，而是打印第二个主题的打印语句并忽略使用第二个主题名称。

Answer 1

如果主题名称只有一个词，您应该使用 input.next() 而不是 input.nextLine()

试试这个：

 Scanner input = new Scanner(System.in);
        System.out.println("Please enter the name of the first subject");
        String A = input.next();
        System.out.println("Please enter marks in subject " + A );
        float a = input.nextFloat();
        System.out.println("Please enter the name of the second subject");
        String B = input.next();
        System.out.println("Please enter the marks of the subject "+ B );
        float b = input.nextFloat();
        System.out.println("Please enter the name of the last subject");
        String C = input.next();

Answer 2

当您使用读取标记的扫描器函数（例如：next()、nextInt()、nextFloat() 等）时，扫描器会读取并 returns 下一个标记。当您读取整行时（即：readLine()），它会从当前位置读取到下一行的开头。

使用这个

Scanner input = new Scanner(System.in);
            System.out.println("Please enter the name of the first subject");
            String A = input.nextLine();
            System.out.println("Please enter marks in subject " + A );
            float a = input.nextFloat();
            System.out.println("Please enter the name of the second subject");
            String B = input.next();
            System.out.println("Please enter the marks of the subject "+ B );
            input.nextLine();
            float b = input.nextFloat();
            input.nextLine();
            System.out.println("Please enter the name of the last subject");
            String C = input.next();

variable.nextInt() 在 Java 程序中不工作

variable.nextInt() not working in Java program

java

input

java.util.scanner