How to Convert List to Array in Java | 2023

Java has several methods for transforming a list into an array. It’s up to you how you want to put it into practice. Using the get(), toArray, and stream API methods, we can transform a list into an array.

List to Array Using .get() Method

get(int index) method is used to access an element at a specific index, In this method, we will traverse on List using For loop and then will access each element using .get() method also will insert the same element in the array.

Code:

package newPackage;
import java.util.*;  
public class BeeTechnical
{  
     public static void main(String[] args)    
     {  
    	 //Initialzing List for holding Integer type objects 
         List<Integer> list = new ArrayList<>();
         
         //Inserting some objects in list
         list.add(3);
         list.add(1);
         list.add(7);
         list.add(10);
         list.add(5);
         
         //Printing list
         System.out.println("List : "+list);
         
         //Initializing an array of same size as list has
         int[] arr = new int[list.size()];
      
         
         //Loop for traversing on list
         for(int i=0;i<list.size();i++)
         {
        	 //Inserting element into array by accessing list's element
        	 //using .get() method
        	 arr[i]=list.get(i);
         }
         
         //Printing Array
         System.out.println("Array : "+Arrays.toString(arr));
     }
} 

Output:

Conversion using toArray() method

In This method, we will use the toArray() method, Which is an in-built method of the List class in Java. For this, we have to declare the data type of our array as Object[].

Code:

package newPackage;
import java.util.*;  
public class BeeTechnical
{  
     public static void main(String[] args)    
     {  
    	 //Initialzing List for holding Integer type objects 
         List<Integer> list = new ArrayList<>();
         
         //Inserting some objects in list
         list.add(3);
         list.add(1);
         list.add(7);
         list.add(10);
         list.add(5);
         
         //Printing list
         System.out.println("List : "+list);
         
         //Initializing array using List's class toArray() method 
         Object[] arr = list.toArray();
      
         
         //Printing Array
         System.out.println("Array : "+Arrays.toString(arr));
     }
} 

Output:

List to Array using Stream API

Stream API in Java Introduced in Java 8, It helps us to process collections of objects. A stream is defined as the sequence of objects that supports various in-built methods.

Code:

package newPackage;
import java.util.*;  
public class BeeTechnical
{  
     public static void main(String[] args)    
     {  
    	 //Initialzing List for holding Integer type objects 
         List<Integer> list = new ArrayList<>();
         
         //Inserting some objects in list
         list.add(3);
         list.add(1);
         list.add(7);
         list.add(10);
         list.add(5);
         
         //Printing list
         System.out.println("List : "+list);
         
         //Conversion by using Stream API 
          Integer[] arr = list.stream().toArray(Integer[] ::new);

         
         //Printing Array
         System.out.println("Array : "+Arrays.toString(arr));
     }
} 

Output:

Conclusion

In conclusion, Java provides multiple methods to convert a List to an array, giving developers the flexibility to choose the approach that works best for their specific use case. Whether you prefer using the get() method, the toArray() method, or the stream API methods, each approach has its own advantages and can be used to transform Lists of various types into arrays. By leveraging these methods, developers can easily transform data structures from Lists to arrays in their Java projects, and enhance the efficiency and flexibility of their code.