You can loop through your array with a for-each loop:

for (x item: GetList()) {
    doSomethingWithEachValue(item);
}

This is a O(2N) solution at some cost of 2N memory instead of N^2 time and N memory cost. Depends on the number of items that you have, but this solution will cost significantly less than the N^2 solutions.

  Set<String> list=new Set<String>();
  for (String area : area_IdList) 
  {  
    list.add(area.toLowerCase());
  }

  for (String duplicatedArea : area_IdListduplicate)
  {
    if(list.contains(duplicatedArea.toLowerCase())){
      //Do something
    }
  }

As for not using index, see Use Enhanced For Loop Syntax

KOTLIN:

val numbers = listOf("one", "two", "three", "four")
for (item in numbers) {
    println(item)
}

or

val numbers = listOf("one", "two", "three", "four")
val numbersIterator = numbers.iterator()
while (numbersIterator.hasNext()) {
    println(numbersIterator.next())
}

Without all the hazzle of try catches and for loops. I could do the same task with one line of code, like following...

int output = stationIDs.get(stationNames.indexOf(stationName));

Thank you all for your help!

Edit:

Well, he edited his post.

If an Object inherits Iterable, you are given the ability to use the for-each loop as such:

for(Object object : objectListVar) {
     //code here
}

So in your case, if you wanted to update your Guns and their Bullets:

for(Gun g : guns) {
     //invoke any methods of each gun
     ArrayList<Bullet> bullets = g.getBullets()
     for(Bullet b : bullets) {
          System.out.println("X: " + b.getX() + ", Y: " + b.getY());
          //update, check for collisions, etc
     }
}

First get your third Gun object:

Gun g = gunList.get(2);

Then iterate over the third gun's bullets:

ArrayList<Bullet> bullets = g.getBullets();

for(Bullet b : bullets) {
     //necessary code here
}

Try this..It will give arrayList of id's

 JSONObject object=new JSONObject(response);
    JSONArray array= null;
    try {
        array = object.getJSONArray("response");
    } catch (JSONException e) {
        e.printStackTrace();
    }

    ArrayList<String> idArray=new ArrayList<>();
    for(int i=0;i< array.length();i++)
    {
        idArray.add(getJSONObject(i).getString("id"));
    }

    public static ArrayList<String> Array = new ArrayList<String>();

    public static ArrayList<String> resim_list=new ArrayList<String>();

In your activity

    Array = bundle.getStringArrayList("string-array");
   // already Array is initalized. no need to initialize again
    GridViewConfig.addImageUrls();// call the add method

GridViewConfig class

    public static class GridViewConfig {
    public static ArrayList<String> resim_list=new ArrayList<String>();

    public static ArrayList<String> getResim_list() {
        return resim_list;
    }

    public void setResim_list(ArrayList<String> resim_list) {
        GridViewConfig.resim_list = resim_list;
    }

    public static void addImageUrls() {
        Set<String> hs = new LinkedHashSet<String>(Array);// set of unique elments 
        // LinkedHashSet maintains insertion order 
        resim_list.addAll(hs);
        for(int i=0;i<resim_list.size();i++)
        {
          System.out.println("NEW RESIM_LIST" + resim_list.get(i));

        }
    }
}

Edit:

Declare this before onCreate()

public  ArrayList<String> Array = new ArrayList<String>();
public  ArrayList<String> resim_list=new ArrayList<String>();

In your onCreate()

Array = bundle.getStringArrayList("string-array");
addImageUrls();

Then define addImageUrls in your activity class as below

      public  void addImageUrls() {
        ArrayList<String> resim_list=new ArrayList<String>();
        Set<String> hs = new LinkedHashSet<String>(Array);// set of unique elments 
        // LinkedHashSet maintains insertion order 
        resim_list.addAll(hs);
        for(int i=0;i<resim_list.size();i++)
        {
          System.out.println("NEW RESIM_LIST" + resim_list.get(i));
        }   
      }  

Array is declared with a class scope. No need to use static modifies. If you intend to use it in another class pass it using intent.

Solved the Problem with the help of a friend:

private void ButtonClick() {
    /** get all values of the EditText-Fields */
    View v;
    ArrayList<String> mannschaftsnamen = new ArrayList<String>();
    EditText et;
    for (int i = 0; i < myList.getCount(); i++) {
        v = myList.getAdapter().getView(i, null, null);
        et = (EditText) v.findViewById(i);
        mannschaftsnamen.add(et.getText().toString());
    }
....
}