HashMap 有三种迭代方式
- 按照键值对迭代遍历
- 按照 key 迭代遍历
- 按照 value 迭代遍历
按照键值对迭代遍历
public static void main(String[] args) {
HashMap a = new HashMap<String,String>();
//插入元素
a.put("101", "苹果");
a.put("102", "橘子");
a.put("103", "香蕉");
//通过键值对遍历
System.out.println("通过键值对遍历");
Iterator<Map.Entry<String, String>> iterator = a.entrySet().iterator();
while(iterator.hasNext()){
Map.Entry<String, String> next1 = iterator.next();
String key = next1.getKey();
String value = next1.getValue();
System.out.println(key+"="+value);
}
//通过 value 遍历
System.out.println("通过 value 遍历");
Iterator iterator3 = a.values().iterator();
while(iterator3.hasNext()){
System.out.println(iterator3.next());
}
按照 key 迭代遍历
· //通过 key 遍历
System.out.println("通过 key 遍历");
Iterator iterator2 = a.keySet().iterator();
while(iterator2.hasNext()){
System.out.println(iterator2.next());
}
按照 value 迭代遍历
//通过 value 遍历
System.out.println("通过 value 遍历");
Iterator iterator3 = a.values().iterator();
while(iterator3.hasNext()){
System.out.println(iterator3.next());
}