if else or Map(), what faster

if else or Map(), what faster

For example I have 280 countries list, I need to compare with ISO codes.
  1. if(Country == "Aruba")
    {
        ISO_Code = "ABW";
    }
    else if(Country == "Afghanistan")
    {
        ISO_Code = "AFG";
    }
Or

  1. ISOcodes = Map();
  2. ISOcodes.put("Aruba","ABW);
  3. ISOcodes.put("Afghanistan","AFG);
  4. country_iso = ISOcodes.get("Aruba");
Some thoughts what option better and why? What code will work faster?

Thanks