HashMap內部維護的是一個內部元素爲Entry的數組,Entry內部存儲的纔是真正的鍵值-值對,所以在遍歷的時候,首先取出數組中的元素即Entry,然後再獲取鍵值或者是值。
(1)不用迭代器
//放入元素
maps.put("wang", 1);
maps.put("li", 2);
maps.put("jiang", 3);
//遍歷
Set<Entry<String, Integer>> entrySet = maps.entrySet();
for(Entry<String, Integer> entry : entrySet){
System.out.println("key is: " + entry.getKey());
System.out.println("value is: " + entry.getValue());
}
(2)使用迭代器
//放入元素
maps.put("wang", 1);
maps.put("li", 2);
maps.put("jiang", 3);
//遍歷
Iterator<Entry<String, Integer>> it = maps.entrySet().iterator();
while(it.hasNext()){
Entry<String, Integer> entry = it.next();
System.out.println("key is " + entry.getKey() + " value is " + entry.getValue());
}