Converting a string[] into a string then split into an array

Question

I need help creating a loop which splits strings. So far I have the code below.

    System.out.println("*FILE HAS BEEN LOCATED*");
    System.out.println("*File contains: \n");
    List<String> lines = new ArrayList<String>();
    while (scan.hasNextLine()) 
    {
      lines.add(scan.nextLine());
    }

    String[] arr = lines.toArray(new String[0]);

    String str_array = Arrays.toString(arr);

    String[] arraysplit;
    arraysplit = str_array.split(":");

    for (int i=0; i<arraysplit.length; i++)
    {
        arraysplit[i] = arr[i].trim();
        System.out.println(arr[i]);
    }

an example of one of the strings would be

        Firstname : Lastname : age

I want it to split the string into another array that looks like:

        Firstname
        Lastname
        age

I still encounter an error when running the code, it seems as though when I convert the array to a string, it puts commas in the string and therefore it causes problems as I'm trying to split the string on : not ,

image:

Could it be that you are making things too complex? "Firstname : Lastname : age".split("\\s*:\\s*") should give you the result you want. — Tim Biegeleisen
– Tim Biegeleisen, Commented Nov 16, 2017 at 13:41
This question still makes no sense at all. You call Arrays.toString(arr) which clearly and obviously writes each array item into one String using a , as the separator and yet you expect it doesn't behave like it is documented. Why? — Tom
– Tom, Commented Nov 16, 2017 at 14:16

Pavneet_Singh · Accepted Answer · 2017-11-16 14:32:59Z

5

Issue : you are using the old array arr to display values and arraysplit will have resultant values of split method so you need to apply trim() on arraysplit's elements and assign back the elements to same indexes

String[] arraysplit;
arraysplit = str_array.split(":");

for (int i=0; i<arraysplit.length; i++)
{
    arraysplit[i] = arraysplit[i].trim();
    //              ^^^^^^^^^^^^ has values with spaces
    System.out.println(arr[i]);
}

System.out.println(arraysplit[i]);

To simplify solution without (list to array and array to string complication)

1.) Create array of length as sizeOfList * 3

2.) split the list element using \\s*:\\s*

3.) Use array copy with jas index of resultant array to keep the track of the array index

    String result[] = new String [lines.size()*3];
    int j=0;
    for (int i=0; i<lines.size(); i++)
    {
        System.arraycopy(lines.get(0).split("\\s*:\\s*"), 0, result, j, 3);
        j+=3;
    }
    System.out.println(Arrays.toString(result));

You can use regex str_array.split("\\s*:\\s*"); where

\\s*:\\s* : \\s* mean zero or more spaces then : character then zero or more spaces

arraysplit = str_array.split("\\s*:\\s*");
// just use values of arraysplit

edited Nov 16, 2017 at 14:32

answered Nov 16, 2017 at 13:39

Pavneet_Singh

37.5k5 gold badges57 silver badges71 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

m1ddleware Over a year ago

Please look at the image I have attached to my question, as I still encounter an error when running the code, it seems as though when I convert the array to a string, it puts commas in the string and therefore it causes problems as I'm trying to split the string on : not ,

Pavneet_Singh Over a year ago

@rxbert is there is chance that your input can have any special character other than alphabets and numbers? if no then easy way is arraysplit = str_array.split("\\s*\\W\\s*");

Youcef LAIDANI · Accepted Answer · 2017-11-16 13:39:55Z

2

Split using this regex \s*:\s*

String[] arraysplit = str_array.split("\\s*:\\s*");

details :

\s* zero or more spaces
followed by lateral character :
followed by \s* zero or more spaces

regex demo

answered Nov 16, 2017 at 13:39

Youcef LAIDANI

60.3k21 gold badges111 silver badges178 bronze badges

1 Comment

m1ddleware Over a year ago

Please look at the image I have attached to my question, as I still encounter an error when running the code, it seems as though when I convert the array to a string, it puts commas in the string and therefore it causes problems as I'm trying to split the string on : not ,

Collectives™ on Stack Overflow

Converting a string[] into a string then split into an array

2 Answers 2

2 Comments

regex demo

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related