how to take inputs seperated by new line

Question

I have an input with the line breaks. I want to convert that string into an array, and for every new line, jump one index place in the array.

If the input is:

100
200
300

Then I need the output to be:

110
210
310

I have used the following code:

public class NewClass {
    public static void main(String args[]) throws IOException {
        BufferedReader br= new BufferedReader(new InputStreamReader(System.in));
        String str=br.readLine();
        String [] arrOfStr = str.split("\n");int b=0;
        for (String a : arrOfStr) {
            b=Integer.parseInt(a);
            int c=b+10;
            System.out.println(c);
        }
     }
}

But it is not giving the desired output. Note: We are not taking the input from text file. We don't know how many inputs are there in test case. We have take inputs in one go.

What exactly is wrong with your code? Have you tried to debug it? — dbf, Jan 28 '17 at 07:52
Use str.split("\r\n") There's a whole thread about it here: http://stackoverflow.com/questions/454908/split-java-string-by-new-line — Waffles, Jan 28 '17 at 07:54
Oh I misunderstood the problem you're having... br.readLine() only reads ONE line. If you want it to read after line breaks you'll have to implement a while loop. str.split won't work for this case. See here: http://stackoverflow.com/a/5516075/3072960 — Waffles, Jan 28 '17 at 08:12
you should use loop for reading from your file and then in while block you must use br.readline for reading each line — aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa, Jan 28 '17 at 08:27

score 0 · Answer 1 · answered Jan 28 '17 at 09:02

You could use a scanner.hasNext() instead as -

public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    // scanner.useDelimiter("\\r\\n"); // if required to delimit the input 
    while (scanner.hasNext()) {
        int c = Integer.parseInt(scanner.next()) + 10;
        System.out.println(c);
    }
}

Using the same Input as yours -

100
200
300

The Output would be -

110
210
310

score 0 · Accepted Answer · answered Jan 28 '17 at 09:04

0

To elaborate on my comment.

    List<Integer> intList = new ArrayList<Integer>();
    BufferedReader br= new BufferedReader(new InputStreamReader(System.in));
    String str = br.readLine();
    while (!str.isEmpty()) {
        intList.add(Integer.parseInt(str)+10);
        str=br.readLine();

    }
    System.out.println(intList);}

This should work, I'm on my phone...

answered Jan 28 '17 at 09:04

Waffles

407
2
10

`readLine()` will return `null` at the end of file, not an empty string. – Holger Jan 30 '17 at 12:21

how to take inputs seperated by new line

2 Answers2