Question

Look at this code:

/*   Implementation to populate List<String[]> schedule  */

public List<String[]> getSchedBySIN(String sin) {
    List<String[]> listBySin = null;

    for (String[] temp : schedule) {
        if(temp[0].equals(sin)) listBySin.add(temp);
    }

    return listBySin;
}

listBySin on the line ...listBySin.add(temp); is underlined with color yellow and Eclipse tells me this: Null pointer access: The variable listBySin can only be null at this location

Why is that? What I want to do is populate listBySin with string arrays from schedule if their first element is equal to sin.

Answer 1

You need to assign a List object to the var.

List<String[]> listBySin = new ArrayList<String[]>();