There are two ways to do this:

1. A for loop
2. Using the iterator method.

for loop:

for(x currentX : GetList()) {
    // Do something with the value
}

This is what's called a "for-each" loop, and it's probably the most common/preferred method of doing this. The syntax is:

for(ObjectType variableName : InCollection)

You could also use a standard for loop:

ArrayList<x> list = GetList();
for(int i=0; i<list.size(); i++) {
     x currentX = list.get(i);
     // Do something with the value
 }

The syntax for this is:

for(someStartingValue; doSomethingWithStartingValue; conditionToStopLooping)

iterator method:

Iterator<x> iterator = GetList().iterator();
while(iterator.hasNext()) {
    x currentX = iterator.next();
    // Do something with the value
}

for (String area : area_IdList) 
{  
    for (String duplicatedArea : area_IdListduplicate)
    {
        if (!area.equalsIgnoreCase(duplicatedArea))
        { 
            // some decision
        }
    }             
}

This is more efficient, goes faster instead of iterating by indexes. So this will check step by step each element in area_IdList with all elements in area_idListduplicate and each time they don't mach, this decision will be made. (If that's what you want achieve)

Assuming list is your List<String> retuned from the function. You may loop over it like:

for (int i=0; i<list.size(); i++) {
    System.out.println(list.get(i));
}

For assigning the EditText, you can just use the index, if you the number of items and it is fixed( which seem to be 5 here):

phoneNumber1.setText(list.get(0));
phoneNumber2.setText(list.get(1));
//so on ...

stationNames here is not an array , but an ArrayList. So, you cannot use .length on it, use .size() :

Even simpler to do :

return stationNames.indexOf(stationName);

if it is found in the list will return its position or -1 if not.

Use

for(String s:result){
if(s.equals(InputActivity.Item1)){
   //hide text view
}
}

You want to follow the same pattern as before:

for (Type curInstance: CollectionOf<Type>) {
  // use currInstance
}

In this case it would be:

for (Bullet bullet : gunList.get(2).getBullet()) {
   System.out.println(bullet);
}

  public void FunctionExample(ArrayList contacts) {

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

        LinkedTreeMap<String, Object> map = (LinkedTreeMap<String, Object>) contacts.get(i);
        map.containsKey("id");
        String id = (String) map.get("id");
        map.containsKey("contact_name");
        String contact_name = (String) map.get("contact_name");
        map.containsKey("numbers");
        String numbers = (String) map.get("numbers");
        numbers.replace("{","").replace("}","");
        map.containsKey("emails");
        String emails = (String) map.get("emails");
        emails.replace("{","").replace("}","");

        Snackbar.make(getView(), id, Snackbar.LENGTH_LONG).show();
        Snackbar.make(getView(), contact_name, Snackbar.LENGTH_LONG).show();
        Snackbar.make(getView(), numbers, Snackbar.LENGTH_LONG).show();
        Snackbar.make(getView(), emails, Snackbar.LENGTH_LONG).show(); 

  }
} 

Your question is not so clear, I suggest you show us your code (how you create the array, the TextView, the button), it will be easier to help you complete it.

What I would do to iterate a String array would be something like this:

String[] myArray={"s1","s2","s3"};
TextView myTextView; //suppose myTextView has already been created and added to your layout
int currentIndex=0;

private void onClick(View v) {
    if (currentIndex<myArray.length) {
        myTextView.setText(myArray[currentIndex]);
        currentIndex++;
    }
}

When you use myList.getAdapter().getView(i,null,null) you are getting a new instance of the item view, try the ListView.getChildAt(position) method like this:

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.getChildAt(i);
        et = (EditText) v.findViewById(R.id.editText1);
        mannschaftsnamen.add(et.getText().toString());
    }
....
}