How to Initialize a List in Java

How to Initialize a List in Java ?

Answer

To initialize a list in Java, you can use the Arrays.asList method for a fixed-size list or the ArrayList class for a resizable list.

✐ Examples

1 Initialize a Fixed-Size List of Integers

In this example,

We use the Arrays.asList method to create a fixed-size list of integers and assign it to the variable fixedSizeList.
The Arrays.asList method takes the elements as arguments and returns a list containing those elements.
We print the list to standard output to verify its contents.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<Integer> fixedSizeList = Arrays.asList(1, 2, 3, 4, 5);
        System.out.println("Fixed-Size List: " + fixedSizeList);
    }
}

Output

Fixed-Size List: [1, 2, 3, 4, 5]

2 Initialize a Resizable List of Strings

In this example,

We use the ArrayList class to create a resizable list of strings and assign it to the variable resizableList.
The ArrayList constructor can be called without arguments to create an empty list or with a collection to initialize the list with elements.
We add a new element to the list using the add method.
We print the list to standard output to verify its contents.

Java Program

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

public class Main {
    public static void main(String[] args) {
        List<String> resizableList = new ArrayList<>();
        resizableList.add("Apple");
        resizableList.add("Banana");
        resizableList.add("Cherry");
        resizableList.add("Date");
        System.out.println("Resizable List: " + resizableList);
    }
}

Output

Resizable List: [Apple, Banana, Cherry, Date]

Summary

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

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How to Initialize a List in Java

How to Initialize a List in Java ?

Answer

✐ Examples

1 Initialize a Fixed-Size List of Integers

Java Program

Output

2 Initialize a Resizable List of Strings

Java Program

Output

Summary

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