How do you copy the components of an ArrayList to a regular Array?

Question

  public boolean makeReservation(int id, AvilaNatalyPassenger request) {
    boolean status = true;
    ArrayList<Integer> inputValues = new ArrayList<Integer>();
        for (int i = 0; i < 22; i++) {
            for (int j = 0; j < 5; j++) {
             id = seats[i][j];
                if (id != -1) {
                    if (inputValues.contains(id)) {
                    status = false;
                    break;
                    }
                    else {
                    inputValues.add(id);
                    for(int a = 0; a < inputValues.size; a++)
                        seats[a] = inputValues[a];

                    }
                }
            }
         }

 return status;
 }

This is what I have but its not correct. I need to add what I have in inputVaule arrayList into the array seats.

I have no idea what this code is supposed to do. Could you please explain what you are trying to achieve, and where it goes wrong? — Keppil, Dec 08 '13 at 19:05
Try with toArray: http://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html#toArray%28T[]%29 — Blub, Dec 08 '13 at 19:06
this method should directly accesses array seats to determine whether the seat is already taken. If not, record the id at that position in seats. Return true if you make the reservation and false if it is already taken. The problem I'm having is adding the positions to seats. — user3026678, Dec 08 '13 at 19:30

score 1 · Answer 1 · answered Dec 08 '13 at 22:20

You can also look at the Java API: http://docs.oracle.com/javase/7/docs/api/index.html?java/util/ArrayList.html

public Object[] toArray()

Returns an array containing all of the elements in this list in proper sequence (from first to last element).

So this is what you could do:

seats[a] = inputValues.toArray();

Furthermore you cannot use inputValues[a] since it is not an array. What you probably could do is

seats[a] = (inputValues.toArray())[a];

score 0 · Answer 2 · edited May 23 '17 at 12:29

0

To answer your question, here is an example:

ArrayList<String> stock_list = new ArrayList<String>();
stock_list.add("stock1");
stock_list.add("stock2");
String[] stockArr = new String[stock_list.size()];
stockArr = stock_list.toArray(stockArr);
for(String s : stockArr)
    System.out.println(s);

Example is taken from here

edited May 23 '17 at 12:29

Community

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answered Dec 08 '13 at 19:08

Stefan Freitag

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I think you can just use `String[] stockArr = stock_list.toArray(stockArr);` – Chronicle Dec 08 '13 at 19:31

How do you copy the components of an ArrayList to a regular Array?

2 Answers2