Java中hashmap遍历

1. Map的四种遍历方式
   下面只是简单介绍各种遍历示例(以HashMap为例)，

(1) for each map.entrySet()
Map map = new HashMap();
for (Entry entry : map.entrySet()) {
entry.getKey();
entry.getValue();
}

(2) 显示调用map.entrySet()的集合迭代器

Iterator> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry entry = iterator.next();
entry.getKey();
entry.getValue();
}
(3) for each map.keySet()，再调用get获取

Map map = new HashMap();
for (String key : map.keySet()) {
map.get(key);
}
(4) for each map.entrySet()，用临时变量保存map.entrySet()
Set> entrySet = map.entrySet();
for (Entry entry : entrySet) {
entry.getKey();
entry.getValue();
}