有點(diǎn)郁悶呀，昨天面了一家，寫完個(gè)人信息才知道原來(lái)是招.net的。我暈！！！
現(xiàn)在只能看看面試題了，順便轉(zhuǎn)點(diǎn)東西。
省得每次都查，直接貼到這里好了~
JDK1.4中
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,應(yīng)用新特性For-Each循環(huán)
Map m = new HashMap();
for(Object o : map.keySet()){
map.get(o);
}
返回的 set 中的每個(gè)元素都是一個(gè) Map.Entry 類型。
private Hashtable<String, String> emails = new Hashtable<String, String>();
//方法一: 用entrySet()
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循環(huán)()
for (Map.Entry<String, String> m : emails.entrySet()) {
logger.info("email-" + m.getKey() + ":" + m.getValue());
}
// 方法三：用keySet()
Iterator it = emails.keySet().iterator();
while (it.hasNext()){
String key;
key=(String)it.next();
logger.info("email-" + key + ":" + emails.get(key));
}
// 方法五：jdk1.5支持，用keySEt()和For-Each循環(huán)
for(Object m: emails.keySet()){
logger.info("email-" + m+ ":" + emails.get(m));
}
另外 我們可以先把hashMap 轉(zhuǎn)為集合Collection，再迭代輸出，不過(guò)得到的對(duì)象
Map aa = new HashMap();
aa.put("tmp1", new Object()); //追加 替換用同樣的函數(shù).
aa.remove("temp1"); //刪除
for (Iterator i = aa.values().iterator(); i.hasNext(); ) {
Object temp = i.next();
} //遍歷
來(lái)個(gè)完整的，包含TreeSet的元素內(nèi)部排序的
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);
hash.put(2, 2);
treeMap.put(1, 1);
treeMap.put(2, 2);
treeMap.put(3, 3);
treeMap.put(4, 4);
treeMap.put(5, 5);
treeMap.put(6, 6);
//list遍歷
for(String m: list){
System.out.println(m);
}
// hashmap entrySet() 遍歷
for(Map.Entry<Object,Object> m: hash.entrySet()){
System.out.println(m.getKey()+"---"+m.getValue());
}
//hashmap keySet() 遍歷
for(Object m: hash.keySet()){
System.out.println(m+"---"+hash.get(m));
}
// treemap keySet()遍歷
for(Object m: treeMap.keySet()){
System.out.println(m+"---"+treeMap.get(m));
}
}