为什么这没有道理？ 删除节点

Question

I have code that takes user input and increments a counter for printing and deleting purposes. I added some print lines to see what the count difference was between the linked list and the current position and this is what I got:

Enter a command from the list above (q to quit): 
2
Deleted: e                e                5                $5.0
 Current record is now first record.
4
5
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 4, Size: 4
        at java.util.LinkedList.entry(LinkedList.java:365)
        at java.util.LinkedList.get(LinkedList.java:315)
        at bankdata.command(bankdata.java:158)
        at bankdata.main(bankdata.java:314)
Java Result: 1
BUILD SUCCESSFUL (total time: 18 seconds)

enter command 2, the remove current node command. The current node is the last in the linked list which is 5 in size which technically means from 0-4.

SO how come when I run this code:

//currentAccount is a static int that was created at the start of my code.
//It got it's size because the int is saved every time a new node is made.
//The most recent size correlates with the last position in the linked list.
            int altefucseyegiv = accountRecords.size();
            System.out.println("Deleted: " + accountRecords.get(currentAccount)
                    + "\n Current record is now first record.");
            System.out.println(currentAccount);
            System.out.println(accountRecords.size());
            accountRecords.remove(currentAccount);
            System.out.println("Deleted: " + accountRecords.get(currentAccount)
                    + "\n Current record is now first record.");
            if(altefucseyegiv == 1)
            {
                currentAccount = -1;
            }
            else
            {
                currentAccount = 0;
            }
            records.currentAcc(currentAccount, accountRecords);
            return;

I get this error???

I'm confused! Because I'm removing the .get(4)th and that means I'm just removing the 5th element and I don't mean love. Can someone explain and possibly help me fix this please?

Answer 1

The IOFB Exception is thrown by the line

System.out.println("Deleted: " + accountRecords.get(currentAccount)
                + "\n Current record is now first record.");

You have removed the 5th element, so now there is no 5th element to show (remember array positions start on 0)

Answer 2

Try

Object obj = accountRecords.remove(currentAccount);
System.out.println("Deleted: " + obj + "\n Current record is now first record.");

I'm assuming you have initialized currentAccount as accountRecords.size() - 1 and accountRecords has 5 nodes.

Then currentAccount has a value 4 and you are removing 4th element from the list leaving accountRecords with only 4 elements.

Then you are trying to fetch accountRecords.get(4) from the list where accountRecords has only 4 elements and the valid element indexes are 0..3 , that is why you are getting the error.

Answer 3

i think your mistake is your println:

System.out.println("Deleted: " + accountRecords.get(currentAccount)
                + "\n Current record is now first record.");

<- you get the IndexOutOfBoundsException because you deleted the last entry of the list, or i am wrong? maybe try:
System.out.println("Deleted: " + accountRecords.get(currentAccount-1) + "\\n Current record is now first record.");