如何在if循环中要求输入特定条件

如何解决如何在if循环中要求输入特定条件

在check_mark（）方法中，如果我为PHYSICS放置了错误的标记（位于第二个位置a [1]），即mark> 100，则进入if循环，它必须要求输入相同的PHYSICS标记，但是，再次从a [0]开始，即MATHS ...与英语相同，再次从MATHS开始。

请帮助我解决这个问题，它必须要求输入错误输入的特定标记...。

故障代码：

import java.util.Scanner;

class averageMark
{
    static int no_of_students=2;
    static int a[]=new int[3];
    static int no_of_subjects=a.length;
    static String b[]=new String[]{"MATHS","PHYSICS","ENGLISH"};
    static int avg;
    static int total_marks=0;
    static Scanner sc=new Scanner(system.in);

    void check_mark()
    {
       for (int j = 0; j < 3; j++) 
       {
           System.out.print("Enter "+b[j]+" mark: ");
           a[j]=sc.nextInt();
           if(a[j]>100)
           {
               System.out.println("Please provide correct mark which is equal to or below 100");
               check_mark();
           }
       }
   }

   public static void main( String[] args )
   {
      for (int i = 0; i < no_of_students; i++) 
      {    
        averageMark check=new averageMark();
        check.check_mark();
        for (int k = 0; k < no_of_subjects; k++) 
        {
            total_marks+=a[k];
        }
        avg=total_marks/no_of_subjects;
        System.out.println();
        System.out.println("The average is: "+avg);
        if(avg>=70)
        {
            System.out.println();
            System.out.println("!!!Qualified!!!");   
        }
        else
        {
            System.out.println();
            System.out.println("!!!Not qualified!!!");
        }
        System.out.println();
    }
    sc.close();
    }
 }

解决方法

如果标记不正确，则不应调用check_mark方法。您应该减少索引

void check_mark() {
   for (int j = 0; j < 3; j++) {
       System.out.print("Enter "+b[j]+" mark: ");
       a[j]=sc.nextInt();
       if(a[j]>100) {
           System.out.println("Please provide correct mark which is equal to or below 100");
           j--;
       }
   }
}

,

您还可以使用while（）循环来实现它；

void check_mark()
    {
       for (int j = 0; j < 3; j++) 
       {
           System.out.print("Enter "+b[j]+" mark: ");
           a[j]=sc.nextInt();

           while(a[j]>100){
               System.out.println("Please provide correct mark which is equal to or below 100");
              a[j] = sc.nextInt(); 
           }
       }
   }