select each value in comma-separated values in java

Question

here is my code and results

what i want is to calculate total balance for each account number, how do i select each account number in distinguish and it's balance to do operations (subtract and add)?

result as follows: Account number , D for debit, C for credit, Balance

Answer 1

For each line that you read in, you could split the string on the comma symbol, eg

String[] transactionLineElements = transactionLine.split(",");

this will give you an array of strings, where the 3rd element (at index 2) is that transaction value/balance - ie transactionLineElements[2]. You can then interpret that transaction value string as a number, eg

BigDecimal balance = new BigDecimal(transactionLineElements[2]);

Similarly, you can parse the account number, eg:

Long accountNumber = Long.valueOf(transactionLineElements[0]);

Answer 2

You have to split the values by a comma, using String.split(String regex) . For example:

String[] values = transactionLine.split(",");  // it can be a regex too
// You should check values.length for if there are less/more values than needed

Then use Long.parseLong(String s) to parse the account number into a long . You might want to use BigInteger.valueOf(String s) instead if your number is very big

long accountNumber = Long.parseLong(values[0]);
// Or use this instead:
BigInteger accountNumber = BigInteger.valueOf(values[0]);

To check if it's credit or debit, remember you must use String.equals(String s) for comparing strings contents, never == :

if (values[1].equals("D")) {
    // debit
}
else if (values[1].equals("C") {
    // credit
}
else {
    // wrong input; you should tell the user here
}