Mega Code Archive
To perform some operation on all keys
public Enumeration keys()
public Set keySet()
The keys() method returns the set of keys as an Enumeration.
The keySet() method returns the set of keys as a Set object.
Which you use depends upon what you wish to do with the keys.
import java.util.Enumeration;
import java.util.Hashtable;
public class MainClass {
public static void main(String[] s) {
Hashtable table = new Hashtable();
table.put("key1", "value1");
table.put("key2", "value2");
table.put("key3", "value3");
Enumeration e = table.keys();
while (e.hasMoreElements()) {
String key = (String) e.nextElement();
System.out.println(key + " : " + table.get(key));
}
System.out.println(table.keySet());
}
}
key3 : value3
key2 : value2
key1 : value1
[key3, key2, key1]