Question

In normal array list initialization,
We used to define generic type as follows,

List<String> list1 = new ArrayList<String>();

But in case of ArrayList of ArrayLists, How can we define its generic type?

The code for array list of array lists is as follows:

ArrayList[] arr=new ArrayList[n];
 for(int i=0;i<n;i++)
 {
 arr[i]=new ArrayList();
 } 

Just share the syntax, if anybody have idea about it..!

Answer 1

You can simply do

List<List<String>> l = new ArrayList<List<String>>();

If you need an array of Lists, you can do

List<String>[] l = new List[n];

and safely ignore or suppress the warning.