diff --git a/javaSE-day04/src/com/inmind/map01/TreeDemo07.java b/javaSE-day04/src/com/inmind/map01/TreeDemo07.java new file mode 100644 index 0000000..b042c1d --- /dev/null +++ b/javaSE-day04/src/com/inmind/map01/TreeDemo07.java @@ -0,0 +1,39 @@ +package com.inmind.map01; + +import java.util.Comparator; +import java.util.TreeSet; + +/* +TreeSet和TreeMap对比学习 + +TreeSet 是 Java 集合框架中一个基于 TreeMap 实现的有序集合,具有以下特点: +元素有序(默认自然排序,也可通过构造方法指定比较器) + */ +public class TreeDemo07 { + public static void main(String[] args) { + // 1. 创建 TreeSet(默认自然排序) + TreeSet treeSet = new TreeSet<>(); + treeSet.add(3); + treeSet.add(2); + treeSet.add(11); + treeSet.add(1); + + System.out.println(treeSet); + + // 2. 创建 TreeSet(指定比较器,如降序排序) + TreeSet treeSet1 = new TreeSet<>(new Comparator() { + @Override + public int compare(Integer o1, Integer o2) { + return o2 - o1; + } + }); + + treeSet1.add(3); + treeSet1.add(2); + treeSet1.add(11); + treeSet1.add(1); + + System.out.println(treeSet1); + + } +}