Question

Is there is a built-in method in Java to sort a 2D array directly

For example: if I have an array of first name & phone number, can I sort it according to the first name while each name will keep it’s phone number using built-in function?

Answer 1

Is your data structure [[name1, name2, ...], [phone1, phone2,...]] or [[name1, phone1], ...]? If it’s the latter, you can use a comparator.

class NameAndPhoneComparator implements Comparator<String[]> {
    public int compare(String[] o1, String[] o2) {
        int c = o1[0].compareTo(o2[0]);
        if (c != 0) return c;
        return o1[1].compareTo(o2[1]);
    }
}

Then use Arrays.sort