how to make a arraylist in java code example

Example 1: how to define an arraylist in java

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

Example 2: how to make an array of arraylists in java

ArrayList<Integer> [] myList = (ArrayList<Integer>[]) new ArrayList[4];