Using and declaring generic List

Question

So I\'m working in Java and I want to declare a generic List.

So what I\'m doing so far is List list = new ArrayList();

But no

Answer 1

You should either have a generic class or a generic method like below:

public class Test<T>  {
    List<T> list = new ArrayList<T>();
    public Test(){

    }
    public void populate(T t){
        list.add(t);
    }
    public static  void main(String[] args) {
        new Test<String>().populate("abc");
    }
}

Answer 2

The T is the type of the objects that your list will contain. You can write List<String> and use it in a function which needs List<T>, it shouldn't be a problem since the T is used to say that it can be anything.

Answer 3

You cannot add the "X"(String) into the list having type of directly so that you need to write a function which accept T as a parameter and add into the List, like

List<T> myList = new ArrayList<T>(0);
public void addValue(T t){
  myList.add(t);
}

and while calling this function you can pass string.

 object.addValue("X");