大文字の全てのアルファベットをアルファベット順で取得する
実装 - Implementation
import java.util.ArrayList; import java.util.List; public class AlphabetUtil { public static List<String> getUpperAlphabets() { final int ALPHABET_SIZE = 'Z' - 'A'; char alphabet = 'A'; List<String> upperAlphabets = new ArrayList<String>(); for (int i = 0; i <= ALPHABET_SIZE; i++) { upperAlphabets.add(String.valueOf(alphabet++)); } return upperAlphabets; } }
テスト - Test
import java.util.List; import org.junit.Test; import static org.junit.Assert.*; public class AlphabetUtilTest { @Test public void shouldGetAllUpperAlphabetInAlphabeticalOrder() { List<String> alphabets = AlphabetUtil.getUpperAlphabets(); assertEquals("A", alphabets.get(0)); assertEquals("B", alphabets.get(1)); assertEquals("C", alphabets.get(2)); assertEquals("D", alphabets.get(3)); assertEquals("E", alphabets.get(4)); assertEquals("F", alphabets.get(5)); assertEquals("G", alphabets.get(6)); assertEquals("H", alphabets.get(7)); assertEquals("I", alphabets.get(8)); assertEquals("J", alphabets.get(9)); assertEquals("K", alphabets.get(10)); assertEquals("L", alphabets.get(11)); assertEquals("M", alphabets.get(12)); assertEquals("N", alphabets.get(13)); assertEquals("O", alphabets.get(14)); assertEquals("P", alphabets.get(15)); assertEquals("Q", alphabets.get(16)); assertEquals("R", alphabets.get(17)); assertEquals("S", alphabets.get(18)); assertEquals("T", alphabets.get(19)); assertEquals("U", alphabets.get(20)); assertEquals("V", alphabets.get(21)); assertEquals("W", alphabets.get(22)); assertEquals("X", alphabets.get(23)); assertEquals("Y", alphabets.get(24)); assertEquals("Z", alphabets.get(25)); } }
−ω− もっとスマートな方法があれば教えてください!