how to make an array of arrays

Question

how would you write an array of values to other array. In instance, I have a list of IPs and list of requests. I want to have something like [{ip1, request1}, {ip2, request2}, ....].

It's how I would do it, but sure obj will change every time and array will have all the time the same values.

ArrayList array = new ArrayList();
    Object[] obj = new Object[2];

    for (int i=0; i<listSize; i++){

        obj[0] = ipList.get(i).toString();
        obj[1] = requestList.get(i);

        array.add(obj);

finnw · Accepted Answer · 2011-01-16 18:43:35Z

2

I think this should be:

ArrayList array = new ArrayList();

for (int i=0; i<listSize; i++){
    Object[] obj = {ipList.get(i).toString(), requestList.get(i)};

    array.add(obj);
}

Also consider creating a new class for obj. (I do not know what it should be called because you did not say what it is for.)

answered Jan 16, 2011 at 18:43

finnw

48.8k24 gold badges150 silver badges223 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

metadaddy · Accepted Answer · 2011-01-16 18:44:48Z

1

Just move the line where you create obj into the loop...

ArrayList array = new ArrayList();

for (int i=0; i<listSize; i++){
    Object[] obj = new Object[2];

    obj[0] = ipList.get(i).toString();
    obj[1] = requestList.get(i);

    array.add(obj);

answered Jan 16, 2011 at 18:44

metadaddy

4,4492 gold badges25 silver badges51 bronze badges

Comments

Navi · Accepted Answer · 2011-01-16 18:49:26Z

0

You are better off with a LinkedHashMap

  Map map = new LinkedHashMap();
  for (int i=0; i<listSize; i++){

    map.put( ipList.get(i).toString(), requestList.get(i) );

    }

answered Jan 16, 2011 at 18:49

Navi

8,7764 gold badges36 silver badges32 bronze badges

1 Comment

finnw Over a year ago

That will only work if the IP addresses are unique (the OP did not specify this.)

Collectives™ on Stack Overflow

how to make an array of arrays

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related