Thread: keep getting main method error need some help =]

i am trying to insert 5 students ids and a
course number for each student id. Then it prints all
5 student ids and the course name associated with
each student id.

but im having trouble with inserting the main method because i have no idea what to input.

package assignment10;
 
import java.util.Scanner;
 
public class BannerWebArray 
{
	public static void main(String[] args)
	{
 
		Scanner scan=new Scanner(System.in);
		int studentId,courseId,i;
		String courseName;
		BannerUser[] bannerUser=new BannerUser[5];
		for (i=0;i<5;i++)
			bannerUser[i]=new BannerUser();
 
		for (i=0;i<5;i++)
		{
			System.out.print("Enter student id:");
			studentId=scan.nextInt();
			System.out.print("Enter course id: 1 for Math, 2 for English");
			courseId=scan.nextInt();
 
			bannerUser[i].setUserId(studentId);
			courseName=bannerUser[i].register(courseId);
			bannerUser[i].setCourseName(courseName);
 
			System.out.println("Students registered for Math:");
			for (i=0;i<5;i++)
			{
 
				courseName=bannerUser[i].getcourseName();
				if (courseName.equals("Math"))
					System.out.println(bannerUser[i].getUserId());
			}
 
			System.out.println("Student registered for English");
			for (i=0;i<5;i++)
			{
				courseName=bannerUser[i].getcourseName();
				if (courseName.equals("English"))
					System.out.println(bannerUser[i].getUserId());
			}
		}
	}
 
}

error message:
Enter student id:12345
Enter course id: 1 for Math, 2 for English2
Students registered for Math:
Exception in thread "main" java.lang.NullPointerException
at assignment10.BannerWebArray.main(BannerWebArray.ja va:33)

now it shows:
Enter student id:1234
Enter course id: 1 for Math, 2 for English2
Students registered for Math:
Exception in thread "main" java.lang.NullPointerException
at bannerwabarray.BannerWebArray.main(BannerWebArray. java:32)
line 31 to 34:

package bannerwabarray;
 
import java.util.Scanner;
 
public class BannerWebArray {
	public static void main(String[] args)
	{
 
		Scanner scan=new Scanner(System.in);
		int studentId,courseId,i;
		String courseName;
		BannerUser[] bannerUser=new BannerUser[5];
		for (i=0;i<5;i++)
			bannerUser[i]=new BannerUser();
 
		for (i=0;i<5;i++)
		{
			System.out.print("Enter student id:");
			studentId=scan.nextInt();
			System.out.print("Enter course id: 1 for Math, 2 for English");
			courseId=scan.nextInt();
 
			bannerUser[i].setUserId(studentId);
			courseName=bannerUser[i].register(courseId);
			bannerUser[i].setCourseName(courseName);
 
			System.out.println("Students registered for Math:");
			for (i=0;i<5;i++)
			{
 
				courseName=bannerUser[i].getcourseName();
				if (courseName.equals("Math"))
					System.out.println(bannerUser[i].getUserId());
			}
 
			System.out.println("Student registered for English");
			for (i=0;i<5;i++)
			{
				courseName=bannerUser[i].getcourseName();
				if (courseName.equals("English"))
					System.out.println(bannerUser[i].getUserId());
			}
		}
	}
 
}

i seriously dont see it . im so lost.

if (courseName.equals("Math"))

Enter student id:1234
Enter course id: 1 for Math, 2 for English1
Students registered for Math:
null
Exception in thread "main" java.lang.NullPointerException
at bannerwabarray.BannerWebArray.main(BannerWebArray. java:33)


so math has the null right?

my computer glitched and all my work got deleted so i had to redo other assigned problems. will be back as soon as i catch back up