Extracting pattern from string with unknown length

Question

I'm still in a very embryonic stage in Java and I am trying to figure out how to extract all specific values.

That are in this form (pattern) [A-H][1-8] out of a String which length is unknown.
So for example if my string is " F5 F4 E3 " I want to assign F5 to a variable, F4 to a variable, E3 to another variable.

Or if my string would be " A2 " I would like to assign A2 to a variable.
I kind of have a feeling that I should use an Array to store the values.
Please note that between the wanted pattern there are blank spaces "blankE2blank".

This is my code so far:

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Arrays;

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

        int i = 0;
        char[] Wanted = new char[]{?}; // What should I use here?
        Pattern pat = Pattern.compile("\\s*d+\\s*D+\\s*d+");
        String Motherstring = " F5 F4 E3 "; // this is just an example but the extraction should work for every string
        Matcher m = pat.matcher(Motherstring);
        while (pat.find()) {
            Wanted[i] = pat; // ?
            i++;
        }
    }
}

Answer 1

You may use \b anchor. Below is hand-written example, I haven't test it. It just shows the idea.

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Arrays;

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

        int i = 0;
        char[] Wanted = new char[3];// Instead of array any dynamic collection should be used here. Since I'm not familiar with Java collections enough, Im leaving array here for correct work
        Pattern pat = Pattern.compile("\\b\\w+\\b");
        String Motherstring = " F5 F4 E3 ";
        Matcher m = pat.matcher(Motherstring);
        while (pat.find()) {
            Wanted[i]= pat.group();
            i++;
        }
    }
}

Answer 2

Don't use an array. Use a List. The size is dynamic and allows you to add objects. See this:

Pattern pattern = Pattern.compile("[A-H][1-8]");
Matcher matcher = pattern.matcher(" F5 F4 E3 ");

// Create a new list (ArrayList) to store Strings.
ArrayList<String> list = new ArrayList<>();

// For every match of the regexp in the test string:
while (matcher.find())
    // Add the match to the list.
    list.add(matcher.group());

System.out.println(list);

Here is an online code demo. The STDOUT prints:

[F5, F4, E3]