Map / HashMap 获取Key值的方法

方法1：keySet()

 

HashMap hashmp = ne HashMap();
hashmp.put("aa", "111");
Set set = hashmp.keySet();
Iterator iter = set.iterator();
while (iter.hasNext()) {
String key = (String) iter.next();
// printkey
}
// traverse
for (String key : list.get(pos).keySet() ) {
myKey = key;
}

 

方法2：entrySet()

 

 

HashMap map;
Iterator i = map.entrySet().iterator();
while (i.hasNext()) {
Object obj = i.next();
String key = obj.toString();
}
// or
while (i.hasNext()) {
Entry entry = (java.util.Map.Entry)it.next();
entry.getkey();
entry.getValue();
}

 

完。我用的方法1，受益匪浅。

 

 

https://coding.imooc.com/class/267.html#Anchor 最近在看这个。