HashMap遍历

 HashMap的循环，如果既需要key也需要value，直接用方法1，

总结四种遍历方式

1. for each map.entrySet()

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

2.显示调用map.entrySet()的集合迭代器

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

3for each map.keySet()，再调用get获取

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

4、 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();}