Java Program Input - "Welcome1","round4","1st3","to2" => output - "Welcome1","to2","1st3","round4"

 import java.util.Arrays;

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

public class sortingStringUsingLastChar {
    public static void main(String[] args) {
        String[] inputArray = {"Welcome1", "round4", "1st3", "to2"};

        System.out.println("Original Array: " + Arrays.toString(inputArray));

        // Sort the array using a custom comparator
        Arrays.sort(inputArray, new NumericStringComparator());

        System.out.println("Sorted Array: " + Arrays.toString(inputArray));
    }

    /**
     * A custom Comparator for sorting alphanumeric strings by the integer value they contain.
     */
    static class NumericStringComparator implements Comparator<String> {
        // Pattern to find the first sequence of digits in a string
        private static final Pattern intsOnly = Pattern.compile("\\d+");

        @Override
        public int compare(String s1, String s2) {
            Integer num1 = extractNumber(s1);
            Integer num2 = extractNumber(s2);

            // If both strings have numbers, compare them numerically
            if (num1 != null && num2 != null) {
                return Integer.compare(num1, num2);
            }
            // Fall back to natural string comparison if numbers aren't found or an issue occurs
            return s1.compareTo(s2);
        }

        /**
         * Extracts the first integer found in the given string.
         * @param s The input string.
         * @return The extracted integer, or null if no integer is found.
         */
        private Integer extractNumber(String s) {
            Matcher matcher = intsOnly.matcher(s);
            if (matcher.find()) {
                try {
                    return Integer.parseInt(matcher.group());
                } catch (NumberFormatException e) {
                    // Handle potential parsing errors gracefully
                    return null;
                }
            }
            return null;
        }
    }
}

output:

Original Array: [Welcome1, round4, 1st3, to2]
Sorted Array: [Welcome1, 1st3, to2, round4]