Key Features of Java Playground
- Interactive Stdout Panel View standard compiler outputs, run logs, and error exceptions instantly.
- Monaco Editor Integration Full Java syntax highlight, indentation matching, and formatting.
- Full Standard Library Utilize util, math, collections, and io classes inside the JVM.
Java Playground Examples
Java Standard Outline
Simple Java program printing to standard output.
Input
public class Main {
public static void main(String[] args) {
System.out.println("Hello, Java!");
}
}Output
Hello, Java!How to Use Java Playground
-
1. Write Java Code
Type your Java program. The entry point must be a public class named Main with a main() method.
-
2. Compile and Run
Click Run or press ⌘↵. Judge0 compiles with javac and executes with the JVM.
-
3. View Output
System.out.println() output and compiler errors appear in the Output panel.
Common Use Cases for Java Playground
- Learning OOP Principles Define classes, encapsulation, polymorphisms, and abstract models.
- Testing Algorithms Write and evaluate recursions, list traversals, or search algorithms.
- Practicing Syntax Exercises Execute Java loops, variables, and arrays manipulation easily.
The Technical Details
The Java Playground submits source code to Judge0, executing it within a secure container-isolated JDK. Stdout, stderr, and run-time statistics are processed client-side asynchronously.
Frequently Asked Questions
Which Java version is used?
Java 17 (OpenJDK) on the Judge0 CE sandbox.
Does my class need a specific name?
Yes. The public class must be named Main so the compiler can locate the entry point.
Can I use Maven or external JARs?
No. Only the Java standard library (java.util, java.io, java.lang, etc.) is available.
Is my code private?
Code is submitted to the public Judge0 CE API. Avoid pasting sensitive data.