java - 为什么我将 Array 转换为 HashSet 后仍有重复的元素

Question

我有一个简单的数组：

String[] names = {"apple","apple","orange","orange"};
System.out.println("length is "+ names.length); //length is 4

我尝试在数组中创建一个没有那些重复元素的集合，因为 Java 文档说Set是一个不包含重复元素的集合，所以我Set用来删除重复的元素：

Set<String> nameSet = new HashSet<String>(Arrays.asList(names));
System.out.println("length is "+ nameSet.size()); //length is 4 still

但是nameSet仍然包含重复的元素，为什么我的 Set 没有独特的元素？

以及如何在不遍历数组的情况下解决我的问题？

Answer 1

您必须运行不同的代码

String[] names = {"apple","apple","orange","orange"};
System.out.println("length is "+ names.length); //length is 4

Set<String> nameSet = new HashSet<String>(Arrays.asList(names));
System.out.println("length is "+ nameSet.size()); //length is 2

按预期打印。

length is 4
length is 2