JAVA PROGRAM • LEVEL 02 — VARIABLES, DATA TYPES & CASTING

Demonstrate Autoboxing and Unboxing in Java

Learn demonstrate autoboxing and unboxing in java with a complete, compiler-ready Java 17 example.

BeginnerWrapper classAutoboxing

PROBLEM UNDERSTANDING

Input and expected output

Sample input
No input required
Sample output
Integer 25

COMPLETE JAVA 17 PROGRAM

Complete Java 17 implementation

java-wrapper-autoboxing.java
Open in compiler
class Main {
    public static void main(String[] args) throws Exception {
        Integer boxed = 25;
        int primitive = boxed;
        System.out.println(boxed.getClass().getSimpleName() + " " + primitive);
    }
}

GUIDED CODE TOUR • NOT LIVE EXECUTION

Study the program line by line

Use the real compiler button above to run and debug with different inputs.

CURRENT STEP

Select Start to walk through the important lines.

SELECTED LINE

No line selected

EXPECTED OUTPUT FOR THE SAMPLE

Integer 25
0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

  1. Initialize the deterministic sample values used for demonstrate autoboxing and unboxing in java.
  2. Apply Wrapper class and Autoboxing in the order shown by the program.
  3. Print the final result and compare it with the documented sample output.

This Java 17 example demonstrates Wrapper class and Autoboxing through a complete, executable program. The values are intentionally small so students can trace each statement, verify the output, and then modify the example safely in the online compiler.

EFFICIENCY

Time and space complexity

Time complexity

O(1)

Auxiliary space

O(1)

DEBUGGING CHECKLIST

Common mistakes

Check this

Keep the class name Main and the entry method signature public static void main(String[] args) when using the online compiler.

Check this

Use Wrapper class with compatible Java types; Java checks types and method signatures at compile time.

Check this

Java is case-sensitive, and every statement that requires a semicolon must end with one.

Try it yourself

Practice: Run the program with the sample input, predict its output, and then test one boundary case of your own.