How to Append a List to another List in Java - Step by Step Examples

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How to Append a List to another List in Java ?

Answer

To append a list to another list in Java, you can use the addAll method of the List interface.

✐ Examples

1 Append List Using addAll Method

In this example,

We create two lists: list1 and list2 with initial values.
We use the addAll method to append all elements of list2 to list1.
Finally, we print the updated list1 to standard output.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<Integer> list1 = new ArrayList<>();
        List<Integer> list2 = List.of(4, 5, 6);
        list1.addAll(list2);
        System.out.println("Updated list: " + list1);
    }
}

Output

Updated list: [4, 5, 6]

2 Append List Using Stream

In this example,

We create two lists: list1 and list2 with initial values.
We use the Stream API to concatenate the elements of list2 to list1.
Finally, we print the updated list1 to standard output.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<Integer> list1 = new ArrayList<>();
        List<Integer> list2 = List.of(4, 5, 6);
        list1.addAll(list2.stream().collect(Collectors.toList()));
        System.out.println("Updated list: " + list1);
    }
}

Output

Updated list: [4, 5, 6]

Summary

In this tutorial, we learned How to Append a List to another List in Java language with well detailed examples.

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How to Append a List to another List in Java - Step by Step Examples

How to Append a List to another List in Java ?

Answer

✐ Examples

1 Append List Using addAll Method

Java Program

Output

2 Append List Using Stream

Java Program

Output

Summary

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