"有没有办法将不可变列表转换为可变列表？"

Question

So I wanted to create a method to add an element into an immutable list but I kinda need it to be a mutable list to be returned at the end. So far, I have have created a mutable copy of the immutable list:

Grid2D add(int elem) {
          List<Integer> newlist = new ArrayList<Integer>();
          for (int i = 0; i < this.list.size(); i++) {
              newlist.add(list.get(i));
          }   
          newlist.add(elem);
          return new Grid2D(newlist, this.numOfCols);
}   

Answer 1

Is there a way to convert an immutable list to a mutable one?

<\/blockquote>

---