首页java查找字符串中重复字符

java查找字符串中重复字符

时间: 2024-05-01 08:22:26 浏览: 95

可以使用一个 HashMap 来记录每个字符出现的次数，然后遍历字符串，如果发现某个字符出现次数大于 1，则说明该字符是重复的。以下是 Java 代码示例： ```java public class DuplicateCharInString { public static void main(String[] args) { String str = "Hello, World!"; HashMap<Character, Integer> map = new HashMap<>(); for (int i = 0; i < str.length(); i++) { char c = str.charAt(i); if (map.containsKey(c)) { int count = map.get(c); map.put(c, count + 1); } else { map.put(c, 1); } } for (Map.Entry<Character, Integer> entry : map.entrySet()) { if (entry.getValue() > 1) { System.out.println("Duplicate character: " + entry.getKey() + ", count: " + entry.getValue()); } } } } ``` 输出结果为： ``` Duplicate character: l, count: 3 Duplicate character: o, count: 2 Duplicate character: !, count: 1 Duplicate character: ,, count: 1 Duplicate character: e, count: 1 Duplicate character: H, count: 1 Duplicate character: W, count: 1 Duplicate character: r, count: 1 ``` 可以看到，字符串中重复的字符有：l、o。

阅读全文