Converting Array into ArrayList - Java

There are serval ways in which we can convert Array into ArrayList in Java, let's take a look at a few examples.

Example 1: Arrays.asList()

import java.util.Arrays;
import java.util.ArrayList;
import java.util.List;

public class ArrayToArrayListExample1 {

    public static void main(String[] args) {

        String[] arrayOfStrings = {"A", "B", "C", "D", "E"};
        

        List<String> list = Arrays.asList(arrayOfStrings);
        
        ArrayList<String> arrayList = new ArrayList<>(list);
        
        System.out.println(arrayList);
    }
}

Output:

Example 2: Using Loops

import java.util.ArrayList;

public class ArrayToArrayListExample2 {

    public static void main(String[] args) {
        String[] arrayOfStrings = {"A", "B", "C", "D", "E"};
        

        ArrayList<String> arrayList = new ArrayList<>();
        

        for (String element : arrayOfStrings) {
            arrayList.add(element);
        }
        
        System.out.println(arrayList);
    }
}

Example 3: Using Java 8 Stream API

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class ArrayToArrayListExample3 {

    public static void main(String[] args) {

        String[] arrayOfStrings = {"A", "B", "C", "D", "E"};
        

        List<String> list = Arrays.stream(arrayOfStrings)
                                  .collect(Collectors.toList());
        

        ArrayList<String> arrayList = new ArrayList<>(list);
        
        System.out.println(arrayList); 
    }
}

Example 4: Collections.addAll()

import java.util.ArrayList;
import java.util.Collections;

public class ArrayToArrayListExample4 {

    public static void main(String[] args) {

        Integer[] arrayOfIntegers = {1, 2, 3, 4, 5};
        
        ArrayList arrayList = new ArrayList<>();
        
        Collections.addAll(arrayList, arrayOfIntegers);
        
        System.out.println(arrayList);
    }
}

Output:

Conclusion:

Use Arrays.asList() for quick, fixed-size list conversion; use a loop for element processing or large arrays; use Collections.addAll() for adding elements to an existing ArrayList; and use the Stream API for functional programming and additional processing in Java 8 and later.