java - 我的 Java System.out.print 似乎略有重叠

Question

我今天一直在做这件事；它是 Java 代码，因此您可以:输入学生数量，输入他们的名字、姓氏、百分比，然后打印出该百分比是多少(通过/优秀)等。

但由于某种原因，仅对于第一个条目，名字和姓氏提示同时出现，因此名字会被姓氏覆盖，甚至无法输入第一个学生的名字。

你能找出问题所在吗？谢谢。

//imports scanner class
import java.util.Scanner;

public class Grades { 

    public static void main(String[] args) { 

        // new scanner called sc
        Scanner sc = new Scanner(System.in); 

        // start off by asking:
        System.out.print("How many students? ");
        // typed in number = number of students
        int count = sc.nextInt();
        // Line break 
        System.out.print("\n");

        // new strings for name/grade and int for percentage
        String fname[] = new String[count]; 
        String lname[] = new String[count]; 
        int percent[]  = new int[count]; 

        System.out.println("A-Z for Name & 0-9 for Percentages Only\n"); 

        // if there's input - add the info in 
        for (int i=0; i<count;i++){ 

            // enter first name
            System.out.print("Enter first name: "); 
            fname[i] = sc.nextLine(); 

            // enter surname
            System.out.print("Enter last name: "); 
            lname[i] = sc.nextLine(); 

            // enter percent
            System.out.print("Enter percentage: "); 
            percent[i] = Integer.parseInt(sc.nextLine());
        }

        // print out some text for information
        System.out.println("\nThe following information displays the students full name, percentage & their grade.");   

        // and print them on screen
        for (int i=0; i<count;i++) { 
            System.out.print("\nStudent - " + fname[i] + " " + lname[i] + " received " + percent[i] + "%."); 

            if (percent[i] >= 00 && percent[i] <= 39)   {System.out.print(" That's a Fail.");}
            if (percent[i] >= 40 && percent[i] <= 64)   {System.out.print(" That's a Pass.");}
            if (percent[i] >= 65 && percent[i] <= 84)   {System.out.print(" That's a Merit.");}
            if (percent[i] >= 85 && percent[i] <= 100)  {System.out.print(" That's a Distinction.");}
            if (percent[i] > 100)                       {System.out.print(" This percentage is too high? please try again.");}
            if (percent[i] < 0)                         {System.out.print(" This percentage is negative? please try again.");}

        }
    }    
}

Answer 1

问题是第一个扫描器的 nextInt() 条目。您可以通过输入数字并按 Enter 键来输入此数据。但 nextInt 只是读取整数，回车符仍然保留在输入中。当代码继续执行时，下一个扫描器 nextLine() 方法将立即读取该回车，因为它仍在输入中。在此过程中将名字留空。为了避免这种情况，您可以在循环之前调用 nextLine()。

您还可以通过始终使用 nextLine() 并将结果字符串解析为第一个问题中的整数来避免这种情况。