util.Arrays vs reflect.Array in Java with Examples

Prerequisite: Array class, Arrays class

The Array class in java.lang.reflect package is a part of the Java Reflection. This class provides static methods to dynamically create and access Java arrays. It is a final class, which means it can’t be instantiated, or changed. Only the methods of this class can be used by the class name itself.

The Arrays class in java.util package is a part of the Java Collection Framework. This class provides static methods to dynamically create and access Java arrays. It consists of only static methods and the methods of Object class. The methods of this class can be used by the class name itself.

Difference between Array and Arrays in Java:

  1. The package of existence:
    The Array class exists in the java.lang.reflect package whereas the Arrays class exists in the java.util package.



    Class Hierarchy of Array:

    java.lang.Object
     ↳ java.lang.reflect
      ↳ Class Array
    

    Class Hierarchy of Arrays:

    java.lang.Object
     ↳ java.util
      ↳ Class Arrays
    
  2. Immutability:
    The Array class is immutable in nature whereas the Arrays class is not. By immutable, it means that the class cannot be extended or inherited. The Array class is declared as final to achieve immutability.

    Class Declaration of Array:

    public final class Array
        extends Object
    

    Class Declaration of Arrays:

    public class Arrays
        extends Object
    
  3. Usage:
    The java.util.Arrays class contains various methods for manipulating arrays (such as sorting and searching) whereas this java.lang.reflect.Array class provides static methods to dynamically create and access Java arrays. This Array class keeps the array to be type-safe.

    Example:

    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    // Java program to show Array vs Arrays
      
    import java.lang.reflect.Array;
    import java.util.Arrays;
      
    public class GfG {
        public static void main(String[] args)
        {
      
            // Get the size of the array
            int[] intArray = new int[5];
      
            // Add elements into the array
            // using reflect.Array class
            Array.setInt(intArray, 0, 10);
      
            // Printing the Array content
            // using util.Arrays class
            System.out.println(
                Arrays.toString(intArray));
        }
    }

    chevron_right

    
    

    Output:

    [10, 0, 0, 0, 0]
    


My Personal Notes arrow_drop_up

Technical Content Engineer at GeeksForGeeks

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.