example arraylist classes in java

Example 1: how to create a list in java

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

class scratch{
    public static void main(String[] args) {
        List<Integer> aList = new ArrayList<>();
        List<Integer> lList = new LinkedList<>();
    }
}

Example 2: java arraylist

import java.util.List; //list abstract class
import java.util.ArrayList; //arraylist class

//Object Lists
List l = new ArrayList();
ArrayList a = new ArrayList();

//Specialized List
List<String> l = new ArrayList<String>();
ArrayList<Integer> a = new ArrayList<Integer>();
//only reference data types allowed in brackets <>

//Initial Capacity
List<Double> l = new ArrayList<Double>(5);
//list will start with a capacity of 5
//saves allocation times