Remove duplicates from an ArrayList in Java

Question

I was taking a test and was stuck with this program can someone help me find a solution?

I want to remove all the duplicate elements in an arraylist.

eg:

1 2 3 1 2 3 4 5 4 5 6  7 8 7 6 7 8
Output:
1 2 3 4 5 6 7 8

Answer 1

Here is the function for doing this.

// Function to remove duplicates from an ArrayList
public static <T> ArrayList<T> removeDuplicates(ArrayList<T> list)
{
    // Create a new ArrayList
    ArrayList<T> newList = new ArrayList<T>();
    // Traverse through the first list
    for (T element : list) {
        // If this element is not present in newList then add it
        if (!newList.contains(element)) {
            newList.add(element);
        }
    }
    // return the new list
    return newList;
}