how to declare an array list of array list in java code example

Example 1: java create arraly list

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

Example 2: how to make an arraylist java

ArrayList<Integer> integerArray = new ArrayList<Integer>();
ArrayList<String> stringArray = new ArrayList<String>();
ArrayList<Double> doubleArray = new ArrayList<Double>();
//... keep replacing what is inside the <> with the appropriate
//data type