Question

I imported a List of Strings from a file and put them into an arrayList. I am trying to chop of the end of these arrays, so I’m putting them into a separate String format

Here is where i set x

x = new ArrayList<BankAccounts>();
try {
    Scanner reader;
    reader = new Scanner( new File("F:\\myCreditUnion.txt") );

    while ( reader.hasNext() )
    {
        String inputLine = reader.nextLine();
        first = inputLine.substring(0, 3);
        second = Double.parseDouble(inputLine.substring(5, inputLine.length()));
        x.add(new BankAccounts(first, second));
    }

    reader.close(); 
}

and this is where i try to chop off the end

double howmuch;
for(int i = 0; i < x.size(); i++)
{
     list.equals(x.get(i));
     howmuch = Double.parseDouble(list.substring(5, list.length()));
}
// x is the list

I am getting a nullpointerexception. Wondering how to fix this, as I am pretty new to programming.

Document i am importing contains a combinations of # and letters such as, 101s 583.58

Answer 1

To assign a value to list you have use list = x.get(i); instead of list.equals(x.get(i));

Update:

• equals() does not assign values it only checks if two objects are equal.

• The value returned by x.get(i) will be a BankAccount so you can’t assign it to list (which is a String)

• You have to either turn the BankAccount into a String by using toString() or you have to get a String out of it by calling one of the BankAccount methods before assigning it to list, how this works depends on the methods provided by the BankAccount class.