无法获得正确的输出

Question

我正在传递一个参数

 public void addStudent(String studentName) 
    {   
      if (studentName != null) 
    {    int[] array = new int[NUM_QUIZZES];    
    for (int i = 0; i < array.length; i++) 
    {     
    array[i] = MIN_GRADE;    
    }    
    quizMarks.put(formatName(studentName), array);  
     } 
       }  
> new student, marks set to 0  
/**   
* returns the quiz marks for a given student   
* @param student   
* @return the array of quiz marks for this student  
*/ public int[] getQuizzes(String student) 
    {   
    int[] array = quizMarks.get(student);   
    if (student != null) 
    {    
    for (int arrays : array)
    {     System.out.println(arrays);    
    }
       }   return array; 
  }  

我想显示标记，但它在StudentDatabase.getQuizzes（StudentDatabase.java:68）中的线程“main”java.lang.NullPointerException中给出了异常：第68行：for（int arrays：array）