I’m getting a fatal: Need to specify how to reconcile divergent branches when trying to pull from the skeleton. #

Git is trying to figure out how to merge the code in the remote (skeleton) and what you have locally. Run git config --global pull.rebase false, then try pulling again. It should work!

I’m getting a NullPointerException in Account.java. What is this? #

A null pointer exception is occurs when you try accessing a field or method of a null object. For instance, let’s say that you try to access a parent account (let’s say you called it parent). However, sometimes a given account won’t have a parent! So, if I try calling parent.getBalance(), since parent is a reference to a null object, and null objects don’t have methods, you’ll get this exception.

You can fix a null pointer exception by first checking to see if the object you’re trying to call a method/ access a field is null.

All my tests are passing locally, but I’m failing one last test on Gradscope for Account.java #

You’re likely not handling overdraft protection correctly. If JediAccount has a parent account EthanAccount, and JediAccount has 5 dollars and EthanAccount has 10 dollars, trying to withdraw 20 dollars from JediAccount should not remove the 5 dollars from JediAccount since the amount in JediAccount and the parent accounts is not enough to cover the withdrawal.

Additionally, remember to return the right boolean for each account!

So…what’s the deal with this iterate method? I don’t understand what’s going on and need a hint. #

For the iterate method, you’re going to need to update your two instance variables - curr and next. Note that they’re both Point objects, so make sure you understand the Point.java class! Updating curr is pretty simple - you just need to make sure that the x-coordinate of curr is assigned to the x-coordinate of next (and the same for the y-coordinate of curr). As for next, use dx and dy to update the existing values by adding them (e.g. add dx to next’s x-coordinate to properly update it). Note that x and y are both private variables, so take advantage of the getter methods to help you access them!

When I run java Account or java Point, it can’t find the main method #

To run a Java file, it needs to define a public static void main(String[] args) method, as an “entry point” for the program to start. For these two files, you won’t be running them directly, but will be running the AccountTest and PathTest files, which do define main.

Paraphrased from Shreyas Kallingal