Sort list of countries

Question

I want to generate a list of all countries in a sorted list. I tried this:

public Map<String, String> getCountryNameCodeList() {

        String[] countryCodes = Locale.getISOCountries();

        Arrays.sort(countryCodes);

        Map<String, String> list = new HashMap<>();

        for (String countryCode : countryCodes) {

            Locale obj = new Locale("", countryCode);

            list.put(obj.getDisplayCountry(), obj.getCountry());
        }

        return list;
    }

But for some reason the list is unsorted. What is the proper way to fort it?

`HashMap` doesn't preserve/guarantee any order. Use `TreeMap` it automatically sorts entries based on keys — Ivan, Jan 04 '19 at 15:58
Side note: don't call your method `getCountryNameCodeList` as this implies that you're returning a list, not a map. — Markus, Jan 04 '19 at 16:03
See also https://stackoverflow.com/questions/922528/how-to-sort-map-values-by-key-in-java — Hulk, Jan 04 '19 at 16:08
Don't call something which is a `Map` `list`. That's just confusing. (And don't call a `Locale` `obj`). Give things meaningful names. — Andy Turner, Jan 04 '19 at 16:08

score 2 · Answer 1 · answered Jan 04 '19 at 16:00

2

HashMap is unsorted, use LinkedHashMap:

This implementation differs from HashMap in that it maintains a doubly-linked list running through all of its entries. This linked list defines the iteration ordering, which is normally the order in which keys were inserted into the map (insertion-order).

Just change

Map<String, String> list = new HashMap<>();

to:

Map<String, String> list = new LinkedHashMap<>();

answered Jan 04 '19 at 16:00

xingbin

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Does he need to call sort() on it or something too before returning it? – John Fantastico Jan 04 '19 at 16:04

Sort list of countries

1 Answers1