import java.util.HashSet; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String str = scanner.nextLine(); scanner.close();//关闭scanner,释放空间 HashSet<Character> hs = new HashSet<>(); //需求:从键盘获取一串字符串,要求去除重复的字符。请使用HashSet解决这一问题 //先遍历字符串 for(int i=0;i<str.length();i++){ //添加到HashSet集合中去 hs.add(str.charAt(i)); } for (char c:hs) { System.out.print(c); } } }