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How to print out all elements in HashTable

Posted on 2010-11-10
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Last Modified: 2012-08-14
I have an assignment asking me to create a hashtable then input all the string from a text file into the hashtable. And finally, print out all the element from hashtable.

to print out all the elements, I created the codes below:



Enumeration e = t.elements();
    while(e.hasMoreElements()){
      System.out.println((String)e.nextElement());
  }

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Besides, I import:

import java.util.Enumeration;
import java.util.Hashtable;

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However, it compiles error. The machine complaints it cannot find the elements() method.

I don't know why. Can somebody please help me?


Thanks

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Comment
Question by:woeishyong
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13 Comments
 
LVL 9

Expert Comment

by:the_b1ackfox
ID: 34108407
plenty of people can help you...   but you should post your code so we too can see why the code is erring out...
0
 
LVL 92

Expert Comment

by:objects
ID: 34108508
Sounds like t is not a Hashtable

>       System.out.println((String)e.nextElement());

that should also be:


      System.out.println(e.nextElement());
0
 

Author Comment

by:woeishyong
ID: 34108526
t is a Hashtable I created.


            HashTable t = new HashTable(0);


And I tried the other way,


Enumeration e = t.keys();
        while (e.hasMoreElements()) {
            String key = (String) e.nextElement();
            System.out.println(key);
        }


it's also compiles error. This time it cannot find method keys.

How can I fix it? Do I need to create a keys() / element() method ?
0
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LVL 92

Expert Comment

by:objects
ID: 34108548
post all your code and i'll have a look
0
 

Author Comment

by:woeishyong
ID: 34108564
import java.io.FileInputStream;
import java.util.Scanner;
import java.util.Enumeration;
import java.util.Hashtable;

public class Hashtable {
public static void main(String[] args) throws Exception {
            
if( args.length != 1 ) return;

            HashTable t = new HashTable(0);
            
Scanner in1 = new Scanner(new FileInputStream(args[0]));
while( in1.hasNext()){
String s = in1.next();
int v = t.getvalue(s);
t.assign(s, v);
}

Enumeration e = t.elements();
    while(e.hasMoreElements()){
      System.out.println((String)e.nextElement());
  }

}
}


0
 
LVL 92

Accepted Solution

by:
objects earned 500 total points
ID: 34108614
> public class Hashtable {

you need to change the name of your class (and the filename)

eg.


public class HashtableTest {
0
 

Author Comment

by:woeishyong
ID: 34108668
Okok, then how can I print out?
0
 
LVL 92

Expert Comment

by:objects
ID: 34108721
same as you currently are
0
 

Author Comment

by:woeishyong
ID: 34108826
I tried, yet still not working. still compiles the same error. Cannot find the elements() method.


cannot find symbol
symbol  : method elements()
location: class HashTable
Enumeration e = t.elements();
0
 
LVL 92

Expert Comment

by:objects
ID: 34108833
>            HashTable t = new HashTable(0);

should be:


            Hashtable t = new Hashtable(0);
0
 
LVL 4

Expert Comment

by:ProgSysAdmin
ID: 34164954
The  t.getvalue(s);
and
t.assign(s, v);
Should give you compile errors as well.  Usually you would use:
t.put("one", 1);

instead.

Are you able to read from a text file ok?
0
 
LVL 27

Expert Comment

by:mrcoffee365
ID: 37445782
This question has been classified as abandoned and is closed as part of the Cleanup Program. See the recommendation for more details.
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