java查找字符串中重复字符
时间: 2024-05-01 15:22:26 浏览: 13
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。