Java By Comparison

Avoid Returning Null

class SpaceNations {

    static List<SpaceNation> nations = Arrays.asList(
            new SpaceNation("US", "United States"),
            new SpaceNation("RU", "Russia")
    );

    static SpaceNation getByCode(String code) {
        for (SpaceNation nation : nations) {
            if (nation.getCode().equals(code)) {
                return nation;
            }
        }
        return null;
    }
}

When there’s no proper value to return in a method call, some programmers just return null. This can harm the stability of your program!

In the code here, we’ve modeled the relationship between country codes and country names in the class SpaceNations. The usage is straightforward: you pass a String into the method, and it returns the corresponding SpaceNation instance—or ...