arraylist methods in java

1import java.util.ArrayList;

1import java.util.ArrayList;
2public class ArrayListExample
3{
4   public static void main(String[] args)
5   {
6      int num = 14;
7      // declaring ArrayList with initial size num
8      ArrayList<Integer> al = new ArrayList<Integer>(num);
9      // append new element at the end of list
10      for(int a = 1; a <= num; a++)
11      {
12         al.add(a);
13      }
14      System.out.println(al);
15      // remove element at index 7
16      al.remove(7);
17      // print ArrayList after deletion
18      System.out.println(al);
19      // print elements one by one
20      for(int a = 0; a < al.size(); a++)
21      {
22         System.out.print(al.get(a) + " ");
23      }
24   }
25}

1import java.util.List; //list abstract class
2import java.util.ArrayList; //arraylist class
3
4//Object Lists
5List l = new ArrayList();
6ArrayList a = new ArrayList();
7
8//Specialized List
9List<String> l = new ArrayList<String>();
10ArrayList<Integer> a = new ArrayList<Integer>();
11//only reference data types allowed in brackets <>
12
13//Initial Capacity
14List<Double> l = new ArrayList<Double>(5);
15//list will start with a capacity of 5
16//saves allocation times

1import java.util.ArrayList;
2ArrayList<Integer> myList = new ArrayList<Integer>();
3myList.add(0);
4myList.remove(0);//Remove at index 0
5myList.size();
6myList.get(0);//Return element at index 0

1ArrayList<String> languages = new ArrayList<String>(); 
2languages.add("PHP");
3languages.add("JAVA");
4languages.add("C#");
5ArrayList<int> numbers = new ArrayList<int>(); 
6numbers.add(9);
7numbers.add(14);
8numbers.add(2);

1// Assign to list variable directly with STREAM FILTER METHID
2ArrayList<String> filteredColors = (ArrayList<String>) colors.stream().filter(x -> x.contains("o")).collect(Collectors.toList());
3
4// Clone and remove unwanted(TRADITIONAL FILTERING)
5filteredColors = (ArrayList<String>) colors.clone();
6filteredColors.removeIf(x -> !x.contains("o"));
7
8// Find specific element
9colors.stream().filter(x -> x.contains("ora")).findFirst().get();