JAVA PROGRAM • LEVEL 09 — CLASSES, OBJECTS & CONSTRUCTORS

Use a Default Constructor in Java

Learn use a default constructor in java with a complete, compiler-ready Java 17 example.

IntermediateDefault constructorField

PROBLEM UNDERSTANDING

Input and expected output

Sample input

No input required

Sample output

Java

COMPLETE JAVA 17 PROGRAM

Complete Java 17 implementation

class Course { String name="Java"; }
class Main { public static void main(String[] args) { Course course=new Course(); System.out.println(course.name); } }

CURRENT STEP

Select Start to walk through the important lines.

SELECTED LINE

No line selected

EXPECTED OUTPUT FOR THE SAMPLE

Java

0%Step 0 of 0

PROGRAM EXPLANATION

Algorithm and explanation

Initialize the deterministic sample values used for use a default constructor in java.
Create the required object and apply Default constructor and Field to its state or behavior.
Print the final result and compare it with the documented sample output.

This Java 17 example demonstrates Default constructor and Field 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

Create an object before accessing instance members; static members can be accessed through the class name.

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.