Map遍历方法
Map map = new HashMap();
Iterator it = map.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry) it.next();
Object key = entry.getKey();
Object value = entry.getValue();
}
JDK1.5中,应用新特性For-Each循环
Java代码
Map m = new HashMap();
for(Object o : map.keySet()){
map.get(o);
}
返回的 set 中的每个元素都是一个 Map.Entry 类型.
private Hashtable<String, String> emails = new Hashtable<String, String>();
另外 我们可以先把hashMap 转为集合Collection,再迭代输出,不过得到的对象
//方法一: 用entrySet()
Java代码
Iterator it = emails.entrySet().iterator();
while(it.hasNext()){
Map.Entry m=(Map.Entry)it.next();
logger.info("email-" m.getKey() ":" m.getValue());
}
// 方法二：jdk1.5支持,用entrySet()和For-Each循环()
Java代码
for (Map.Entry<String, String> m : emails.entrySet()) {
logger.info("email-" m.getKey() ":" m.getValue());
}
// 方法三：用keySet()
Java代码
Iterator it = emails.keySet().iterator();
while (it.hasNext()){
String key;
key=(String)it.next();
logger.info("email-" key ":" emails.get(key));
}
// 方法四：jdk1.5支持,用keySEt()和For-Each循环
Java代码
for(Object m: emails.keySet()){
logger.info("email-" m ":" emails.get(m));
}
Map aa = new HashMap();
aa.put("tmp1", new Object());
//追加 替换用同样的函数.
aa.remove("temp1");
//删除
for (Iterator i = aa.values().iterator(); i.hasNext(); ) { Object temp = i.next(); }
//遍历
来个完整的,包含TreeSet的元素内部排序的
Java代码
public static void main(String[] args) {
ArrayList<String> list = new ArrayList<String>();
HashMap<Object,Object> hash = new HashMap<Object,Object>();
TreeMap<Object,Object> treeMap = new TreeMap<Object,Object>();
list.add("a");
list.add("b");
list.add("c");
hash.put(3, 3);
hash.put(4, 4);
hash.put(5, 5);
hash.put(6, 6);
hash.put(1, 1);