import java.util.HashMap;
import java.util.Map;public class Test {
public static void main(String[] args) {
Map<String, String> m = new HashMap<String, String>();
m.put("1", "QQ");
m.put("2", "QQ");
m.put("a", "QQ");
m.put("as", "QQ");
m.put("222", "QQ");欲把key列或者value列分别打印出来怎么做?
foreach(String s: keys){
System.out.println(s+":"+m.get(s));
}
貌似这样的
map.values();得到所有value,返回collection类型
Map<String,String> map = new HashMap<String,String>();
map.put("A", "ACCESS");
map.put("B", "BOUND");
map.put("C", "CYCLE");
map.put("D", "DOUBLE");
Set<Map.Entry<String, String>> entry = map.entrySet();
for(Map.Entry<String, String> e : entry) {
System.out.println("key:"+e.getKey()+"-value:"+e.getValue());
}
{
System.out.println("key:" + entry.getKey() + "value:"
+ entry.getValue());
}
m.put("1", "QQ");
m.put("2", "QQ");
m.put("a", "QQ");
m.put("as", "QQ");
m.put("222", "QQ");
for(Iterator iter=m.entrySet().iterator();iter.hasNext();){
Map.Entry<String, String> entry=(Map.Entry<String, String>)iter.next();
System.out.println("key: "+entry.getKey()+" value: "+entry.getValue());
}
********************************************************************************************
key: 2 value: QQ
key: 222 value: QQ
key: 1 value: QQ
key: a value: QQ
key: as value: QQ
foreach(String s: keys){
System.out.println(s+":"+m.get(s));
} 得到所有的key值
m.values();得到所有的value值for(Iterator iter=m.entrySet().iterator();iter.hasNext();){
Map.Entry<String, String> entry=(Map.Entry<String, String>)iter.next();
System.out.println("key: "+entry.getKey()+" value: "+entry.getValue());
}
得到装有Entry对象的Set集合,里面的属性是key,value
map.values();得到所有value,返回collection类型
Map<String,String> map = new HashMap<String,String>();
map.put("A", "ACCESS");
map.put("B", "BOUND");
map.put("C", "CYCLE");
map.put("D", "DOUBLE");Set<Map.Entry<String, String>> entry = map.entrySet();for(Map.Entry<String, String> e : entry) {
System.out.println("key:"+e.getKey()+"-value:"+e.getValue());
}