Programming Assignment Help

Question

Hello guys, I am a little rusty on my Java programming skills and I need some assistance with an assignment. I have created the program below and I keep getting the following error:
Exception in thread "main" java.lang.NullPointerException
*     at MemoryManager.main(MemoryManager.java:22)*
but I am not sure why. I created a class called MemoryTable, but have not set any methods yet (at the bottom). Any assistance is appreciated.
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import java.util.Scanner;
public class MemoryManager
     public static void main(String[] args)
          String partitionlength;
          int numofpartitions;
          Scanner input = new Scanner(System.in);
          System.out.println("How many partitions are there?");
          partitionlength = input.nextLine();
          numofpartitions = Integer.parseInt(partitionlength);
          System.out.println("There will be " + numofpartitions + " partitions.");
          MemoryTable[] mtable = new MemoryTable[numofpartitions];
          for(int i = 0; i < numofpartitions; i++)
               mtable.partitionsize = (100 + i);
               System.out.println(mtable[i].partitionsize);
_________________________________________________________________________import java.util.*;
public class MemoryTable
     int partitionsize;
     int memoryaddress;
     int access;
     int partitionstatus;
     public MemoryTable()
     partitionsize = 0;
     memoryaddress = 0;
     access = 0;
     partitionstatus = 0;
     public void SetPartitionSize()
     public void SetNumOfPartitions()

Answer 1

OK. I don't completely understand what you meant by that, but this is what I tried, and I still get the error.
================================
import java.util.Scanner;
public class MemoryManager
     public static void main(String[] args)
          String partitionlength;
          int numofpartitions;
          Scanner input = new Scanner(System.in);
          System.out.println("How many partitions are there?");
          partitionlength = input.nextLine();
          numofpartitions = Integer.parseInt(partitionlength);
          System.out.println("There will be " + numofpartitions + " partitions.");
          MemoryTable[] mtable = new MemoryTable[numofpartitions];
          for(int i = 0; i < numofpartitions; i++)
               mtable.partitionsize = 100 + i;
               mtable[i].memoryaddress = 0;
               mtable[i].access = 0;
               mtable[i].partitionstatus = 0;
               System.out.println(mtable[i].partitionsize);