Count number of lines that starts with & character in CSV file

Question

I am trying to make a function that will count how many lines starts with & in given file. So far i came up with following function

  public int CountNumberOfTexts(String filename)  {

        try{

            File file = new File(filename);

            if(file.exists()){

                FileReader fr = new FileReader(file);
                LineNumberReader lnr = new LineNumberReader(fr);

                int linenumber = 0;

                while (lnr.readLine() != null){
                    if (lnr.readLine().substring(0,1) == "&") {
                        linenumber++;
                    }
                }

                Log.d("Count", "NUMBER OF LINES: " + linenumber);

                lnr.close();

                return linenumber;

            }else{
                System.out.println("File does not exists: " + filename);
            }

        }catch(IOException e){
            e.printStackTrace();
        }

        return 0;
    }

Current Function error is: Not recognizing lines starting with & character.

score 2 · Accepted Answer · edited Mar 01 '20 at 16:38

2

You are facing two problems:

You are reading in two lines, but only evaluating every second:

while (lnr.readLine() != null){  <- first consumption
if (lnr.readLine().substring(0,1) == "&") { <- second

You are comparing strings with == operator instead of equals method. Or in your case you can even use startsWith method which is created precisely for scenarios like yours.

This will do the trick:

String line;
while ((line = lnr.readLine()) != null){
    if (line.startsWith("&")) {

edited Mar 01 '20 at 16:38

Pshemo

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answered Mar 01 '20 at 16:33

s.fuhrm

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Works perfectly. Correct answer! – Tagyoureit Mar 01 '20 at 17:00

Count number of lines that starts with & character in CSV file

1 Answers1