HashMap 的遍历方法

1.for each map.entrySet()

for (Entry<String, String> entry : map.entrySet()) {
entry.getKey();
entry.getValue();
}

2.for each map.keySet()

Map<String, String> map = new HashMap<String, String>();
for (String key : map.keySet()) {
map.get(key);
}

3.for each map.entrySet()，用临时变量保存map.entrySet()

Set<Entry<String, String>> entrySet = map.entrySet();
for (Entry<String, String> entry : entrySet) {
entry.getKey();
entry.getValue();
}

4.Iterator迭代器

Iterator<Map.Entry<String, String>> iterator = map.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<String, String> entry = iterator.next();
entry.getKey();
entry.getValue();
}