對List進行排序:java
import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; public class T { public static void main(String[] args) { ArrayList list = new ArrayList(); list.add("92.8"); list.add("68.9"); list.add("168.61"); list.add("242"); list.add("317"); list.add("105"); // 字符串排序 Collections.sort(list); System.out.println(list.toString()); // [105, 168.61, 242, 317, 68.9, 92.8] Collections.sort(list, new Comparator() { @Override public int compare(Object o1, Object o2) { return new Double((String) o1).compareTo(new Double((String) o2)); } }); System.out.println(list.toString()); // [68.9, 92.8, 105, 168.61, 242, 317] } }
Collections.sort(list)是以字典序的形式對字符串進行排序,若是咱們想要按照本身的意願對list進行排序,就須要重寫compare()方法,上述是將字符串轉化爲double類型進行排序。ide