How to combine two array list and show in a listview in android

Question

I want to combine two ArrayList into a single one.

My first arraylist looks like this:

{a,s,d,f,g,h,......} 

My second arraylist looks like this:

{z,x,c,v,b,.....} 

Then I want to combine both to be as

  {a,s,d,f,g,h,.....,z,x,c,v,b.....} 

First List is

ArrayList<String> firstname1   = new ArrayList<String>(); 

Where as the second list is as

ArrayList<String> first   = new ArrayList<String>(); 

Now I want to combine all this together and I want it to be listed out in list view. How to do this?

Answer 1

Combine two ArrayList into a single one

firstname1.addAll(first); 

Please refer this article for sample code to concat two lists.

How to show these items in list view :

your layout should be ( as I used main.xml)

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_marginTop="0dip" android:background="@android:color/transparent">     <ListView             android:id="@+id/custom_list_view"             android:layout_width="fill_parent"             android:layout_height="fill_parent"             android:cacheColorHint="#00000000"             android:fastScrollEnabled="true"             android:background="@android:color/transparent"             android:fadeScrollbars="true"             android:layout_gravity="top"             android:padding="2dp">     </ListView> </LinearLayout>  

and now Activity as CustomListView.java

public class CustomListView extends Activity {      ArrayList<String> firstname1;     ArrayList<String> first;      /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.main);          firstname1 = new ArrayList<String>();         first = new ArrayList<String>();         //Let both array list having some data          firstname1.add("firstname1_data1");         firstname1.add("firstname1_data2");         firstname1.add("firstname1_data3");         firstname1.add("firstname1_data4");         firstname1.add("firstname1_data5");         firstname1.add("firstname1_data6");         firstname1.add("firstname1_data7");         firstname1.add("firstname1_data8");         firstname1.add("firstname1_data9");         firstname1.add("firstname1_data10");          first.add("first_data1");         first.add("first_data2");         first.add("first_data3");         first.add("first_data4");         first.add("first_data5");         first.add("first_data6");         first.add("first_data7");         first.add("first_data8");         first.add("first_data9");         first.add("first_data10");          //Now copying value of first to firstname, as your requirement         //Please refer http://www.java-examples.com/append-all-elements-other-collection-java-arraylist-example for sample code to concat two lists.         firstname1.addAll(first);          //Lets show your data into list view          // Get a handle to the list view         ListView lv = (ListView) findViewById(R.id.custom_list_view);          lv.setAdapter(new ArrayAdapter<String>(CustomListView.this,                 android.R.layout.simple_list_item_1, firstname1));         //Please refer http://developer.android.com/reference/android/widget/ListView.html for details of setAdapter()     } } 

Happy coding.