How do you split a string into a 2d array and access each grouping based on row?

Question

I would like to know how I can separate a string and assign it to a specific row of a 2d array automatically in the same fashion that the single dimensional array is instantiated below:

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

    String file1description= "We went to the mall yesterday.";
    String[] file1tags;
    String delimiter= " ";
    file1tags = file1description.split (delimiter);
    for (int i = 0; i < file1tags.length; i++) {
      System.out.println (file1tags[i]);
    }
  }
}

If there are any simpler ways please share. As you can tell I am quite a novice, but I am willing to learn. In this example, each word is separated by the delimiter and stored automatically into the "file1tags" array. How can I do this with a 2d array, so that I can call multiple arrays that have this same function? Thanks in advance!

user unknown · Accepted Answer · 2012-03-29 13:45:37Z

1

public static String [][] to2dim (String source, String outerdelim, String innerdelim) {

    String [][] result = new String [source.replaceAll ("[^" + outerdelim + "]", "").length () + 1][]; 
    int count = 0;
    for (String line : source.split ("[" + outerdelim + "]"))
    {
        result [count++] = line.split (innerdelim);
    }
    return result;
}

public static void show (String [][] arr)
{
    for (String [] ar : arr) {
        for (String a: ar) 
            System.out.print (" " + a);
        System.out.println ();
    }
}   

public static void main (String args[])
{
    show (to2dim ("a b c \n d e f \n g h i", "\n", " "));
}

newbie friendly:

public static String [][] to2dim (String source, String outerdelim, String innerdelim) {
    // outerdelim may be a group of characters
    String [] sOuter = source.split ("[" + outerdelim + "]"); 
    int size = sOuter.length;
    // one dimension of the array has to be known on declaration:
    String [][] result = new String [size][]; 
    int count = 0;
    for (String line : sOuter)
    {
        result [count] = line.split (innerdelim);
        ++count;
    }
    return result;
}

edited Mar 29, 2012 at 13:45

answered Mar 29, 2012 at 11:30

user unknown

36.4k12 gold badges77 silver badges123 bronze badges

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

5 Comments

user1299661 Over a year ago

Thanks a lot, but is there a newbie version of this?

user unknown Over a year ago

@user1299661: Yes, now there is, and a corrected original. "[ \t]" is a regex for blank or tab, for example - a group of possible delimiters can be defined that way.

user1299661 Over a year ago

Thank you so much for your time and patience! I greatly appreciate it!

user1299661 Over a year ago

I was unable to compile your code.3 errors found: Error: Syntax error on tokens, ClassHeader expected instead Error: Syntax error on token ";", { expected after this token Error: Syntax error, insert "}" to complete ClassBody

user unknown Over a year ago

Well, you have to provide a class header (I'd suggest: public class To2DimStringArray {), an import java.util.*; before that, and if you use the so called newbie-code, the main and show method, as well as a closing brace for the class.

ControlAltDel · Accepted Answer · 2012-03-29 18:02:59Z

1

here's a simple example


String example = "a b c \n d e f \n g h i";
String[] rows = example.split("\n");
for (int i = 0; i < rows.length; i++) {
  String[] columns = rows[i].split(" ");
  for (int j = 0; j < columns.length; j++) {
    //do something
  }
}

edited Mar 29, 2012 at 18:02

answered Mar 29, 2012 at 3:07

ControlAltDel

35.3k10 gold badges60 silver badges86 bronze badges

3 Comments

ControlAltDel Over a year ago

sry it got tripped up on my less thans! Didn't know I had to html encode them

user1299661 Over a year ago

Where did the variable lines get instantiated?

ControlAltDel Over a year ago

sry in my previous edit I changed lines to rows, but I didn't make the change everywhere

Peter · Accepted Answer · 2012-10-29 21:19:38Z

0

String example = "a b c \n d e f \n g h i";
String[] rows = example.split("\n");
String[][] table;
for (int i = 0; i < rows.length; i++) {
  table[i] = rows[i].split(" ");
}

answered Oct 29, 2012 at 21:19

Peter

85410 silver badges20 bronze badges

Collectives™ on Stack Overflow

How do you split a string into a 2d array and access each grouping based on row?

3 Answers 3

5 Comments

3 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

5 Comments

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related