Solved

convert a hashtable to arraylist

Posted on 2003-12-09
7
4,549 Views
Last Modified: 2007-12-19
Hi ,
Can I convert a HashTable to an ArrayList

thx
0
Comment
Question by:applekanna
  • 4
  • 3
7 Comments
 
LVL 92

Accepted Solution

by:
objects earned 100 total points
ID: 9909825
depends if you want the valkues or keys.
to get the keys use:

ArrayList list = new ArrayList(ht.values());

to get the keys:

ArrayList list = new ArrayList(ht.keySet());
0
 
LVL 3

Author Comment

by:applekanna
ID: 9909858
One question what is the differnce between

using constructor
ArrayList list = new ArrayList(ht.values());

and typecasting
ArrayList list = (ArrayList ) ht.values();

Thx
0
 
LVL 92

Expert Comment

by:objects
ID: 9909880
> using constructor
> ArrayList list = new ArrayList(ht.values());

Creates a new instance of ArrayList

> and typecasting
> ArrayList list = (ArrayList ) ht.values();

Assigns list to the collection returnurned by values().
This will only work if the return instance is an instance of ArrayList (which I'm pretty sure it's not).
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 
LVL 3

Author Comment

by:applekanna
ID: 9910038
So is typecasting is only used when return type is of object and of other primitive types like char to int is it?

0
 
LVL 92

Expert Comment

by:objects
ID: 9910092
eg. if you have an ArrayList containing Strings':

String s = (String) mylist.get(0);
0
 
LVL 3

Author Comment

by:applekanna
ID: 9910108
thx for ur help :)
0
 
LVL 92

Expert Comment

by:objects
ID: 9910116
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
In this post we will learn how to connect and configure Android Device (Smartphone etc.) with Android Studio. After that we will run a simple Hello World Program.
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
Viewers will learn about if statements in Java and their use The if statement: The condition required to create an if statement: Variations of if statements: An example using if statements:

863 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

24 Experts available now in Live!

Get 1:1 Help Now