Adding a value to string array in android

Question

as to add values to single as well as 2dim array dynamically, but while adding values it shows null pointer ,

here is my code

Arr points1[];
    points1 = new Arr[listItemList.size()];

    for(int i=0;i<listItemList.size();i++)
    {

        ListItemReminderSummary listItem = listItemList.get(i);
        Log.i("listItem.Car_Id", listItem.Car_Type);

        points1[i].Car_Id = listItem.Car_Id;
        points1[i].Car_Type =  listItem.Car_Type;

    }
    for(int i=0;i<listItemList.size();i++)
    {

         System.out.println( points1[i].Car_Id +  points1[i].Car_Type);
    }

Null pointer at points1[i].Car_Id = listItem.Car_Id;

any suggestion, thnx in advance.

How about using `ArrayList` instead of using simply an `Array` ? — Chintan Soni, Jan 02 '14 at 13:18
actually m ussing arraylist which i want to convert it into array — pitu, Jan 02 '14 at 13:19
Then may be this link could help you: http://stackoverflow.com/q/5374311/1739882 — Chintan Soni, Jan 02 '14 at 13:21

Gopal Gopi · Answer 1 · 2014-01-02T13:18:57.877

1

initialize the items in Array...

for (int i = 0; i < listItemList.size(); i++) {
        ListItemReminderSummary listItem = listItemList.get(i);
        Log.i("listItem.Car_Id", listItem.Car_Type);
        points[i] = new Arr();
        points1[i].Car_Id = listItem.Car_Id;
        points1[i].Car_Type = listItem.Car_Type;
}

edited Jan 02 '14 at 13:18

answered Jan 02 '14 at 13:07

Gopal Gopi

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when i use your second method it give error of 01-02 02:15:35.127: E/AndroidRuntime(960): java.lang.ArrayStoreException: source[0] of type com.example.ListItemReminderSummary cannot be stored in destination array of type com.example.Arr[] – pitu Jan 02 '14 at 13:16
first, check your ArrayList contains items. – Gopal Gopi Jan 02 '14 at 13:35
yes Log.i("listItem.Car_Id", listItem.Car_Type); it prints the value on log – pitu Jan 02 '14 at 13:36

score 0 · Answer 2 · answered Jan 02 '14 at 13:07

0

You have to initialize cells of array.

 for(int i=0;i<listItemList.size();i++){
 points[i] = new Arr();
 }

answered Jan 02 '14 at 13:07

Adam Radomski

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Vivek Warde · Answer 3 · 2014-01-02T13:27:52.467

You have not Allocated memory to the Arr that is why you're trying to dereference an uninitialised pointer (i.e. writing to a random chunk of memory), which is undefined behaviour.

Change ur starting 2 lines

Arr points1[] = new Arr[listItemList.size()];


for (int i = 0; i < listItemList.size(); i++)
{
    ListItemReminderSummary listItem = listItemList.get(i);
    Log.i("listItem.Car_Id", listItem.Car_Type);
    points1[i].Car_Id = listItem.Car_Id;
    points1[i].Car_Type = listItem.Car_Type;
}

score 0 · Answer 4 · answered Jan 02 '14 at 13:33

0

Did you make sure that listItemList.get(i) returns a value? Perhaps there is nothing returned from this.

answered Jan 02 '14 at 13:33

AnOldSoul

4,017
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Adding a value to string array in android

4 Answers4