CodeGym/Help with Java Tasks/Tested and seemd right. Not much to be done wrong here an...

Level 23

Cairns

13.01.2021
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Tested and seemd right. Not much to be done wrong here anyways. But computer says no

Question about the task

Words with numbers

Java Core, Level 9, Lesson 11

Under discussion

Test input:

file1 con4tains l5ines 6with 7words 8separated 9by spaces.
Write to file2 all the words that contain numbers, for example, a1 or abc3d. Separate the words with spaces.

output to 2nd file:

file1 con4tains l5ines 6with 7words 8separated 9by file2 a1 abc3d.

am I missing something here?

The main method's first parameter is file1 and the second is file2.
file1 contains lines with words separated by spaces.
Write to file2 all the words that contain numbers, for example, a1 or abc3d. Separate the words with spaces.
Close the streams.

Requirements:

The program must NOT read data from the console.
The program must read the first file's contents (use the FileReader constructor with a String parameter).
The file input stream (FileReader) must be closed.
The program should write all the words containing numbers from the first file to the second file (use FileWriter).
The file output stream (FileWriter) must be closed.

package com.codegym.task.task19.task1923; /* Words with numbers */ import java.io.FileReader; import java.io.FileWriter; import java.io.IOException; import java.util.ArrayList; public class Solution { public static void main(String[] args) throws IOException { String f1 = args[0]; String f2 = args[1]; FileReader in = new FileReader(f1); FileWriter out = new FileWriter(f2); StringBuilder sb = new StringBuilder(); while (in.ready()){ sb.append((char)in.read()); } String txt = sb.toString(); String[] words = txt.split(" "); for(int i= 0; i<words.length; i++){ char[] temp = words[i].toCharArray(); for(int p = 0; p < temp.length; p++){ if (Character.isDigit(temp[p])){ out.write(words[i]+ " "); break; } } } in.close(); out.close(); } }

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Nouser

Level 36 , Germany

14 January 2021, 07:44

useful

my test words..: file1 con4tains l5ines 6with 7words 8separated last word in the test contains a number 9by Output of my solution: 'file1 con4tains l5ines 6with 7words 8separated 9by' Output of yours: 'file1 con4tains l5ines 6with 7words 8separated 9by '

MoJo

Level 23 , Cairns, Australia

Expert

14 January 2021, 17:09

might have worked, but i updated the code to get rid of the blank as follows:

for(int i= 0; i<words.length; i++){

            char[] temp = words[i].toCharArray();
            for(int p = 0; p < temp.length; p++){
                if (Character.isDigit(temp[p])){

                    //out.write(words[i]+ " ");
                    s = s+words[i] + " ";
                    break;

                }
            }
        }

        s = s.substring(0, s.length()-1);

        out.write(s);
        out.close();

And it still didn't validate with the same reason.

Nouser

Level 36 , Germany

14 January 2021, 17:48

Separate the words with spaces. You add linebreaks as well mine: file1 con4tains l5ines 6with 7words 8separated 9by 1this add2 2 file8 yours: file1 con4tains l5ines 6with 7words 8separated 9by 1this add2 2 file8 test file: file1 con4tains l5ines 6with 7words 8separated last word in the test contains a number 9by 1this is the second line, it should add2 here nums as well 2 the out file8 in the same line Besides that I'm out of ideas :(

MoJo

Level 23 , Cairns, Australia

Expert

15 January 2021, 15:03

So i could not get rid of the linebreaks. Tried .replace("\n", " ") on serveral positions, and if((char) == '\n'){sb.append" ").... i don't know man. So i just copied the given right solution

public class Solution {
    public static void main(String[] args) {

        try (BufferedReader fileReader = new BufferedReader(new FileReader(args[0]));
             FileWriter fileWriter = new FileWriter(args[1])) {
            String fileReadLine;
            String[] splitedLine;
            while ((fileReadLine = fileReader.readLine()) != null) {
                splitedLine = fileReadLine.split(" ");
                for (String word : splitedLine) {
                    if (word.matches(".+[0-9].+")) {
                        fileWriter.write(word + " ");
                    }
                }
            }
        } catch (IOException ignore) {
            /* NOP */
        }
    }
}

which validated ofc. But then in tested it on your input: file1 con4tains l5ines 6with 7words 8separated last word in the test contains a number 9by 1this is the second line, it should add2 here nums as well 2 the out file8 in the same line and I got this as a result: con4tains l5ines That's it lol. I'm moving on but i didn't get it...

Nouser

Level 36 , Germany

15 January 2021, 15:15

The linebreaks aren't that easy to detect as they can differ on the different OSes. On some machines it's just \n on others \r \r\n etc. so in the worst case you'll have to check consecutive bytes. The easiest possibility is to read entire lines (that removes the linebreak) and append a space. That way you have the asked format in the beginning. Also worth a try would be to use replaceAll(lb, " "); with lb being System.getProperty("line.separator") but I have no clue if that will work...

Guadalupe Gagnon

Level 37 , Tampa, United States

15 January 2021, 16:06

I agree. When I read in data from a file, not using a buffer stream, I remove all line breaks like this:

String data = /* data from file */;
data.replaceAll("\r", ""); // first just remove carriage returns
data.replaceAll("\n", " "); // then replace remaining line breaks with space

As Nouser mentioned, the format of line breaks will always include the new line char, while the carriage return may or may not be there. You can safely remove any CRs and only replace the NL chars.

MoJo

Level 23 , Cairns, Australia

Expert

15 January 2021, 18:17

OK, there was something similar once, but I don`t think that`s even the Problem here, since i´m pretty sure i have not seen this problem in other questions that were accepted eventually without addressing this Problem. BUT can we please talk about the "right" solution, that does so much wrong??

Guadalupe Gagnon

Level 37 , Tampa, United States

15 January 2021, 18:32

useful

In your original code, with the correction of the added space, does changing line 33 to:

String[] words = txt.replaceAll("\r","").replaceAll("\n", " ").split(" ");

pass the task?

MoJo

Level 23 , Cairns, Australia

Expert

16 January 2021, 20:21

This does result in not having a line brake anymore, however i can't check if it would make me pass the task, since i cheated an used the given CodeGym solution. I know not good. The best way to avoid LBs would have probably been to use BufferedReader's .readLine(), but it was stated that one is to use FileReader (even tho they used BufferedReader in the given solution).

Guadalupe Gagnon

Level 37 , Tampa, United States

16 January 2021, 21:05

BufferedReader is just an extension class that provides greater functionality to any class that extends the abstract class 'Reader'. Examples of Classes that can be passed in to the BR constructor are: FileReader InputStreamReader StringReader PipedReader CharArrayReader Creating a FileReader as the type to use in the BufferedReader satisfies this task. They should change the task instructions, however, so it specifically says that a Reader as opposed to an InputStream should be used.

MoJo

Level 23 , Cairns, Australia

Expert

17 January 2021, 12:47

OK, thanks. I was wondering why it had to be that one specifically since they are all inherent of Reader. I'll try BufferedReader in the future.