How to Join Lists in Java - Step by Step Examples

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How to Join Lists in Java ?

Answer

To join lists in Java, you can use the `addAll` method to combine multiple lists into a single list.

✐ Examples

1 Join Two Lists of Integers

In this example,

We create two lists named list1 and list2 with integer values.
We create a new list named joinedList and use the addAll method to add all elements from list1 and list2 to joinedList.
Finally, we print the joined list to verify the result.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<Integer> list1 = Arrays.asList(1, 2, 3);
        List<Integer> list2 = Arrays.asList(4, 5, 6);
        List<Integer> joinedList = new ArrayList<>();
        joinedList.addAll(list1);
        joinedList.addAll(list2);
        System.out.println("Joined List: " + joinedList);
    }
}

Output

Joined List: [1, 2, 3, 4, 5, 6]

2 Join Multiple Lists of Strings

In this example,

We create three lists named listA, listB, and listC with string values.
We create a new list named resultList and use the addAll method to add all elements from listA, listB, and listC to resultList.
Finally, we print the joined list to verify the result.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<String> listA = Arrays.asList("apple", "banana");
        List<String> listB = Arrays.asList("cherry", "date");
        List<String> listC = Arrays.asList("fig", "grape");
        List<String> resultList = new ArrayList<>();
        resultList.addAll(listA);
        resultList.addAll(listB);
        resultList.addAll(listC);
        System.out.println("Joined List: " + resultList);
    }
}

Output

Joined List: [apple, banana, cherry, date, fig, grape]

Summary

In this tutorial, we learned How to Join Lists in Java language with well detailed examples.

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How to Join Lists in Java - Step by Step Examples

How to Join Lists in Java ?

Answer

✐ Examples

1 Join Two Lists of Integers

Java Program

Output

2 Join Multiple Lists of Strings

Java Program

Output

Summary

More Java Lists Tutorials