java遍历hashmap
时间: 2023-06-01 22:05:29 浏览: 69
可以的,您可以使用Iterator或者foreach循环来遍历HashMap。例如:
```
HashMap<String, Integer> map = new HashMap<>();
map.put("apple", 1);
map.put("banana", 2);
map.put("orange", 3);
// 使用Iterator遍历HashMap
Iterator<String> iterator = map.keySet().iterator();
while (iterator.hasNext()) {
String key = iterator.next();
Integer value = map.get(key);
System.out.println(key + " : " + value);
}
// 使用foreach循环遍历HashMap
for (String key : map.keySet()) {
Integer value = map.get(key);
System.out.println(key + " : " + value);
}
```
相关问题
java遍历HashMap
Java遍历HashMap有多种方法,以下是其中的几种:
1.使用Iterator遍历HashMap
```java
Map<String, Integer> map = new HashMap<>();
Iterator<Map.Entry<String, Integer>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<String, Integer> entry = iterator.next();
String key = entry.getKey();
Integer value = entry.getValue();
System.out.println("key:" + key + ", value:" + value);
}
```
2.使用For-Each循环遍历HashMap
```java
Map<String, Integer> map = new HashMap<>();
for (Map.Entry<String, Integer> entry : map.entrySet()) {
String key = entry.getKey();
Integer value = entry.getValue();
System.out.println("key:" + key + ", value:" + value);
}
```
3.使用Lambda表达式遍历HashMap
```java
Map<String, Integer> map = new HashMap<>();
map.forEach((key, value) -> System.out.println("key:" + key + ", value:" + value));
```
4.使用Stream API遍历HashMap
```java
Map<String, Integer> map = new HashMap<>();
map.entrySet().stream().forEach(entry -> System.out.println("key:" + entry.getKey() + ", value:" + entry.getValue()));
```
java 遍历hashmap
要遍历一个 HashMap,你可以使用迭代器或者 foreach 循环来逐个访问其中的键值对。以下是使用迭代器遍历 HashMap 的示例代码:
```java
HashMap<String, Integer> map = new HashMap<>();
map.put("A", 1);
map.put("B", 2);
map.put("C", 3);
Iterator<Map.Entry<String, Integer>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<String, Integer> entry = iterator.next();
String key = entry.getKey();
Integer value = entry.getValue();
System.out.println(key + ": " + value);
}
```
你也可以使用 foreach 循环来遍历 HashMap:
```java
HashMap<String, Integer> map = new HashMap<>();
map.put("A", 1);
map.put("B", 2);
map.put("C", 3);
for (Map.Entry<String, Integer> entry : map.entrySet()) {
String key = entry.getKey();
Integer value = entry.getValue();
System.out.println(key + ": " + value);
}
```