java 收藏について文字列の长さによる比较

Posted 2021-05-08

class StringLengthComparator implements Comparator<String> {
	@Override
	public int compare(String o1, String o2) {
		return o1.length() - o2.length();
	}
}

class ComparatorSample {
	public static void main(String... args) {
		List<String> list = Arrays.asList("xyz", "abc", "defghi");
		// 下記2行は同じ動作
		Collections.sort(list, new StringLengthComparator());
		list.sort(new StringLengthComparator()); // Java8以降
		System.out.println(list); // => [xyz, abc, defghi] を出力
	}
}