CodeGym/Help with Java Tasks/I can't seem to find the right regex for the hypen..

Level 22

17.11.2020
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I can't seem to find the right regex for the hypen..

Question about the task

Resolved

I tried so many of them. A little help is appreciated.. Thanks..

The first parameter of the main method is a file name.
Each line of the specified file has the following format:
name month day year
where [name] is a String that can contain several words separated by spaces.
[month] is an int, [day] is an int, and [year] is an int.
The data is separated by spaces.

Fill the PEOPLE list using the file's data.
Close the streams.

Example input file:
John Jack Johnson 12 31 1987 Vincent 5 15 2013

Requirements:

The Solution class must contain a public List<Person> constant called PEOPLE, which must be initialized immediately.
The program must NOT read data from the console.
The program must read the file's contents (use FileReader).
The file input stream (FileReader) must be closed.
The program must fill the PEOPLE list with data from the file.
The program should properly handle hyphenated names, such as Mary-Jo.

package com.codegym.task.task19.task1921; import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.Locale; /* John Johnson */ public class Solution { public static final List<Person> PEOPLE = new ArrayList<>(); public static void main(String[] args) throws FileNotFoundException { try(BufferedReader fileReader = new BufferedReader(new FileReader(args[0]))) { SimpleDateFormat sdf = new SimpleDateFormat("MM dd yyyy", Locale.ENGLISH); while(fileReader.ready()) { String line = fileReader.readLine(); String name = line.split("\\d+")[0]; Date birthday = sdf.parse(line.replaceAll("^[-\\d+ ]", "").trim()); PEOPLE.add(new Person(name, birthday)); } } catch (IOException | ParseException e) { e.printStackTrace(); } } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

18 November 2020, 14:42

solution

This isn't the task to use a regex on. It doesn't say if the names in the file are European, Asian, Middle Eastern, Slavik, African, or from some recently discovered native tribe in some random jungle on the globe. All would have different chars present. It does tell you that each line in the file will be in this format: "name month day year" and that "name" can be multiple words. The task is simple. Get the date, which you know exactly where it is, and then the rest is the name.

Maria

Level 34 , Utrecht, Netherlands

18 November 2020, 11:09

useful

String name = line.replaceAll("\\d+", "").trim();

- replace all numbers and spaсes in the end

Date date = sdf.parse(line.replaceAll("[a-zA-z-]", "").trim());

- replace all letters and spaces and also I would add a catch block for FileNotFoundException

Guadalupe Gagnon

Level 37 , Tampa, United States

18 November 2020, 14:42

see my comment

Nouser

Level 36 , Germany

18 November 2020, 08:50

useful

I wanted to use regex and came up with this:

String name = input.replaceFirst("([A-Za-z\\- ]+)([0-9 ]+)","$1").trim();
String date = input.replaceFirst("([A-Za-z\\- ]+)([0-9 ]+)","$2").trim();

validated even if it probably will fail on '3rd'

Guadalupe Gagnon

Level 37 , Tampa, United States

18 November 2020, 14:42

see my comment

Guadalupe Gagnon

Level 37 , Tampa, United States

17 November 2020, 21:07

hyphen??

Seferi

Level 22 , United Federation of Planets

17 November 2020, 22:24

Hyphens.. ? The last condition: The program should properly handle hyphenated names, such as Mary-Jo.

Guadalupe Gagnon

Level 37 , Tampa, United States

18 November 2020, 01:28

useful

Take what you know, that the last part of the string will be the date, take that off and the rest will be the name. "some name crazy something-what the 3rd 5 15 1987" from the 3rd to last space to end |-------------| is the date |-------------------------------------------------------| the beginning to that space is the name

Seferi

Level 22 , United Federation of Planets

18 November 2020, 09:40

Date birthday = sdf.parse(line.substring((line.length() - 10)).trim());
String name = line.substring(0, line.length() - 10).trim();

Like this? Is there a better way?

Seferi

Level 22 , United Federation of Planets

18 November 2020, 09:44

This is the end result which is working on my IDE but doesn't validate:

public class Solution {
    public static final List<Person> PEOPLE = new ArrayList<>();

    public static void main(String[] args) throws FileNotFoundException {

        try(BufferedReader fileReader = new BufferedReader(new FileReader(args[0]))) {
            SimpleDateFormat sdf = new SimpleDateFormat("MM dd yyyy", Locale.ENGLISH);
            while(fileReader.ready()) {
                String line = fileReader.readLine();
                Date birthday = sdf.parse(line.substring((line.length() - 10)).trim());
                String name = line.substring(0, line.length() - 10).trim();
                PEOPLE.add(new Person(name, birthday));
                }

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

Guadalupe Gagnon

Level 37 , Tampa, United States

18 November 2020, 14:21

Take these for example, to get the proper split: "... 1 1 2015" <--- this would be 10 from the end of length "... 12 1 2015" <--- this would be 11 from the end of length "... 12 11 2015" <--- this would be 12 from the end of length