Question

我正在做一个家庭作业问题，并且我的循环部分存在问题

/**
 * Created by wilson on 2/25/2014.
 */
import java.util.Scanner;
public class GradesDemo {
    public static void main(String[] args) {
        Grades grade = new Grades();
        String name;
        double score = 0;
        boolean invalid = true;
        Scanner keyboard = new Scanner(System.in);
        //One loop iteration for each student

        for (int i = 0; i < 5; i++) {
            invalid = true;
            //Asks for student name, and stores to array
            System.out.println("Student's Name:");
            name = keyboard.nextLine();
            grade.setName(name, i);

            //while loop to check if score entered by user is valid
            while (invalid == true) {
                System.out.println("Student's Score:");
                score = keyboard.nextDouble();
                //Check if score entered was valid. If not, user will be asked again
                if (score >= 0 && score <= 100)
                    invalid = false;
                else
                    System.out.println("Score is invalid. Must be between 0-100. Try again.");
            }
            grade.setScore(score, i);
            //Calculate grade
            grade.findGrade(i);
        }

        for (int i = 0; i <5; i++) {
            System.out.println(grade.toString(i));
        }
    }
}

输出样本：

Student's Name:
John Doe
Student's Score:
88
Student's Name:
Student's Score:

正如您所看到的，在循环的第二次迭代中，它会直接跳过等待学生姓名下的用户输入到学生分数，从而导致错误。

Answer 1

使用BufferReader而不是使用Scanner，它将解决所有这些问题。

while循环导致nextLine（）跳过

1 个答案: