Java 8 ArrayList examples create forEach shuffle

ArrayList is important data structure for many computer languages. Java's ArrayList is used to store lists of numerical data and to represent vectors, matrices, tables. ArrayList is designed to handle variety of different data and it's considered with relatively good performance(for rational size). The java arraylist has a good set of methods for creating, manipulating, shuffling, sorting and iterating over arrays.

Create ArrayList

There are many ways to create and populate ArrayList in Java 8. Here you can find several:

create arraylist of Objects

Objects are from type Language and add members with list.add:

List<Language> list = new ArrayList<>();    	
list.add(new Language(1, "Java7"));
list.add(new Language(2, "Java8"));

create ArrayList of Strings

and add members with method asList:

List<String> list = Arrays.asList("Java7", "Java8", "Java9");

Iterate ArrayList

In Java 8 you can iterate over ArrayList in several ways:

using simple for loop:

List<String> list = Arrays.asList("Java7", "Java8", "Java9");
for(String element : list){
	System.out.println(element);
}

using forEach:

List<String> list = Arrays.asList("Java7", "Java8", "Java9");
list.forEach(element->System.out.println(element));

Output:

Java7, Java8, Java9

Using method reference:

List<String> list = Arrays.asList("Java7", "Java8", "Java9");
list.forEach(System.out::println);

Output:

Java7, Java8, Java9

Search in ArrayList

You can easily search in array list as shown from the examples:

using forEach:

List<String> list = Arrays.asList("Java7", "Java8", "Java9");
list.forEach(element->{
	if("Java8".equals(element)){
		System.out.println(element);
	}
});

Output:

Java8

Using method reference:

List<String> list = Arrays.asList("Java7", "Java8", "Java9");
list.stream()
	.filter(s->s.contains("Java9"))
	.forEach(System.out::println);

Output:

Java9

Randomize ArrayList

Shuffling or randomizing an ArrayList can be done by using Collections :

import java.util.Collections;

Collections.shuffle(list);