Retrieving an element from array list in Android?

Question

I am trying to implement voice recognition code in Android. How do I get an element at a particular position from array list in Android? I tried converting arraylist

Answer 1

What I understand your question is that you want to fetch an element in an ArrayList at a specific location.

Suppose your list contains Integers 1,2,3,4,5 and you want to fetch the value 3. Then the following lines of code will work.

ArrayList<Integer> list = new ArrayList<Integer>();
        if(list.contains(3)){//check if the list contains the element
            list.get(list.indexOf(3));//get the element by passing the index of the element
        }

Either ways you could use list.get(list.lastIndexOf(3))

Answer 2

In arraylist you have a positional order and not a nominal order, so you need to know in advance the element position you need to select or you must loop between elements until you find the element that you need to use. To do this you can use an iterator and an if, for example:

Iterator iter = list.iterator();
while (iter.hasNext())
{
    // if here          
    System.out.println("string " + iter.next());
}

Answer 3

public class DemoActivity extends Activity {
    /** Called when the activity is first created. */
    ArrayList<String> al = new ArrayList<String>();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);



        // add elements to the array list

        al.add("C");
        al.add("A");
        al.add("E");
        al.add("B");
        al.add("D");
        al.add("F");

        // retrieve elements from array

        String data = al.get(pass the index here);
        System.out.println("Data is "+ data);

This is another way of getting element

        Iterator<String> it = al.iterator();
        while (it.hasNext()) {
            System.out.println("Data is "+ it.next());
        }
    }

Answer 4

I have a list of positions of array to retrieve ,This worked for me.

  public void create_list_to_add_group(ArrayList<Integer> arrayList_loc) {
     //In my case arraylist_loc is the list of positions to retrive from 
    // contact_names 
    //arraylist and phone_number arraylist

    ArrayList<String> group_members_list = new ArrayList<>();
    ArrayList<String> group_members_phone_list = new ArrayList<>();

    int size = arrayList_loc.size();

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

        try {

            int loc = arrayList_loc.get(i);
            group_members_list.add(contact_names_list.get(loc));
            group_members_phone_list.add(phone_num_list.get(loc));


        } catch (Exception e) {
            e.printStackTrace();
        }


    }

    Log.e("Group memnbers list", " " + group_members_list);
    Log.e("Group memnbers num list", " " + group_members_phone_list);

}

Answer 5

Maybe the following helps you.

arraylistname.get(position);

Answer 6

U cant try this

for (WordList i : words) {
     words.get(words.indexOf(i));
 }