Convert list to array in Java

Difference between List and Array in Java

Methods to Convert List to array in Java

Here, we will learn about different methods that we can use to convert list to array in java. There are three methods that we can use. These are:

1.  Using get( ) method
2.  Using toArray( ) method
3.  Using Stream introduced in java8

Method 1: Using get( ) method

The method returns the element at a given index from the specified array. It is an inbuilt method in Java. We can use below this method to convert list to array in java with the help of an example.

Syntax: 

public E get(int index)

Example:

• Java

Java

// program to Convert List to Array in java
import java.io.*;
import java. util.LinkedList;
import java.util.List;
class codingninjas {
    // Main method
    public static void main(String[] args)
    {
        List<String> list = new LinkedList<String>();
        list.add("coding");
        list.add("ninjas");
        list.add("Coding Ninjas Studio");
        list.add("Practice");   
        String[] arr = new String[list.size()];
        for (int i = 0; i < list.size(); i++)
            arr[i] = list.get(i);
        for (String x: arr)
            System.out.print(x + " ");
    }
}

You can also try this code with Online Java Compiler

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Output: 
 

Method 2: Using toArray( ) method

This method has to use a toArray( ) form in Java. This method is used to return all the elements in the proper sequence. We can use below this method with the help of an example.

Syntax:

public Object[] toArray()

           or

public <T> T[] toArray(T[] a)

Example:

• Java

Java

// program to Convert List to Array in java
import java.util.*;
public class Codingninjas {
     // Main method
    public static void main(String[] args)
    {
        List<String> list = new LinkedList<String>();
        list.add("coding");
        list.add("ninjas");
        list.add("code");
        list.add("Practice");
        String[] arr = list.toArray(new String[0]); 
        for (String x: arr)
            System.out.print(x + " ");
    }
}

You can also try this code with Online Java Compiler

Run Code

Output: 

 You can compile java code just by clicking here.

Method 3: Using Stream introduced in java8

In this method, the stream API is used to process collections of objects. We can use this method to convert list to array in java.

Example:

• Java

Java

// program to Convert List to Array in java
import java.util.*;
class codingninjas {
    // Main method
    public static void main(String[] args)
    { 
        List<String> list = new LinkedList<String>();      
        list.add("coding");
        list.add("ninjas");
        list.add("code");
        list.add("Practice");
         // Storing size of List
        int n = list.size();
       String[] arr = list.stream().toArray(String[] ::new);
            for (String x : arr)
            System.out.print(x + " ");
    }
}

You can also try this code with Online Java Compiler

Run Code

Output: 

You can also find the output of this java compiler code here.

Algorithm to Convert a List to Array in Java

1. Create a List: Begin by having a list containing elements.
2. Specify Array Type: Determine the type of array that will be created based on the type of elements in the list.
3. Allocate Array: Allocate an array of appropriate size to hold all elements from the list.
4. Copy Elements: Iterate through the list and copy each element to the corresponding position in the array.
5. Return Array: Once all elements are copied, return the array containing the elements from the list.

Must Read Difference between ArrayList and LinkedList, Duck Number in Java

Frequently Asked Questions

How do you convert a list to an array in Java?

Using the .toArray( )method is the easiest and best way to convert a list into an array.

Why toArray( ) method is used in Java?

This method can be used to return an array containing all the elements in ArrayList in the correct order.

Can you convert an ArrayList to an array?

We can use the toArray() method to convert the Arraylist to an array in Java. 

Can we convert a list to a String array in Java?

Yes, we can convert a list to a string array in java by converting ArrayList to an Object array by using the toArray( )method. Here the list converts into string type and is added to the string array.

Conclusion

In this article, we have learned about how to convert list to array in java and the difference between both functions. We have also seen the programming and some examples which convert the list into an array.

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