//HashMap的介紹
import java.util.HashMap;
public class MapTest1
{
public static void main(String[] args)
{
HashMap map = new HashMap();
map.put("a", "zhangsan");
map.put("b", "lisi");
map.put("c", "wangwu");
map.put("a", "zhaoliu");
//System.out.println(map);
String value = (String)map.get("b");
System.out.println(value);
System.out.println("--------------");
String value2 = (String)map.get("d");
System.out.println(value2);
}
}
public class MapTest2
{
public static void main(String[] args)
{
HashMap map = new HashMap();
String str = new String("zhangsan");
map.put("a", str);
map.put("a", str);
System.out.println(map);
}
}
public class MapTest3
{
public static void main(String[] args)
{
HashMap map = new HashMap();
map.put("a", "aa");
map.put("b", "bb");
map.put("c", "cc");
map.put("d", "dd");
map.put("e", "ee");
Set set = map.keySet();
for(Iterator iter = set.iterator(); iter.hasNext();)
{
String key = (String)iter.next();
String value = (String)map.get(key);
System.out.println(key + "=" + value);
}
}
}
public class MapTest4
{
public static void main(String[] args)
{
HashMap map = new HashMap();
for(int i = 0; i < args.length; i++)
{
if(map.get(args[i]) == null)
{
map.put(args[i], new Integer(1));
}
else
{
Integer in = (Integer)map.get(args[i]);
in = new Integer(in.intValue() + 1);
map.put(args[i], in);
}
}
Set set = map.keySet();
for(Iterator iter = set.iterator(); iter.hasNext();)
{
String key = (String)iter.next();
Integer value = (Integer)map.get(key);
System.out.println(key + " : " + value);
}
}
}
public class MapTest5
{
public static void main(String[] args)
{
HashMap map = new HashMap();
map.put("a", "aa");
map.put("b", "bb");
map.put("c", "cc");
map.put("d", "dd");
Set set = map.entrySet();
for(Iterator iter = set.iterator(); iter.hasNext();)
{
Map.Entry entry = (Map.Entry)iter.next();
String key = (String)entry.getKey();
String value = (String)entry.getValue();
System.out.println(key + " : " + value);
}
}
}