Java Autoboxing and Unboxing

In this tutorial, we will learn about the Java Autoboxing and Unboxing with the help of an example.

Autoboxing: Converting a primitive value into an object of the corresponding wrapper class is called autoboxing. For example, converting int to Integer class.
Unboxing: Converting an object of a wrapper type to its corresponding primitive value is called unboxing. For example conversion of Integer to int.

Example 1:

Java AutoBoxing

import java.util.ArrayList;

class Codemistic {
   public static void main(String[] args) {

      ArrayList list = new ArrayList<>();

      //autoboxing
      list.add(5);
      list.add(6);

      System.out.println("ArrayList: " + list);
   }
}

Output:

ArrayList: [5, 6]

Example 2:

Java Unboxing

import java.util.ArrayList;

class Codemistic {
   public static void main(String[] args) {

      ArrayList list = new ArrayList<>();

      //autoboxing
      list.add(5);
      list.add(6);

      System.out.println("ArrayList: " + list);

      // unboxing
      int a = list.get(0);
      System.out.println("Value at index 0: " + a);
   }
}

Output:

ArrayList: [5, 6]
Value at index 0: 5