Java to JavaScript Converter

What is Java to JavaScript Converter?

The Java to JavaScript Converter is a free online tool that transforms Java source code into equivalent JavaScript code. While Java and JavaScript are fundamentally different languages (despite the similar names), many syntactic patterns can be directly translated, making migration and learning easier.

Our converter handles common Java constructs including classes, methods, variable declarations, loops, conditionals, and popular API calls like System.out.println to console.log. It's perfect for developers transitioning between languages or learning JavaScript from a Java background.

Features

• Class Conversion: Transforms Java classes to ES6 JavaScript classes
• Method Translation: Converts Java methods to JavaScript functions
• Variable Types: Removes Java type declarations and uses let/const
• Console Output: Converts System.out.println to console.log
• String Methods: Translates Java string methods to JavaScript equivalents
• Array Handling: Converts Java arrays and ArrayList to JavaScript arrays
• Loop Conversion: Transforms for-each loops to for...of syntax
• Exception Handling: Converts try-catch blocks with proper syntax
• Lambda Support: Converts Java lambdas to arrow functions
• Comment Preservation: Optionally keeps or removes code comments

How to Convert Java to JavaScript

1. Paste Java Code: Enter your Java code in the left editor panel
2. Configure Options: Choose whether to preserve comments, use arrow functions, or use const/let
3. Click Convert: Press the "Convert to JS" button to transform your code
4. Get Results: View the converted JavaScript in the right panel
5. Copy or Download: Copy the result to clipboard or download as a .js file

Conversion Examples

public class HelloWorld { public static void main(String[] args) { System.out.println("Hello, World!"); } }

class HelloWorld { function main() { console.log("Hello, World!"); } }

public int add(int a, int b) { int sum = a + b; return sum; } String name = "John"; boolean isActive = true;

add(a, b) { const sum = a + b; return sum; } const name = "John"; const isActive = true;

String[] fruits = {"apple", "banana"}; for (String fruit : fruits) { System.out.println(fruit); } for (int i = 0; i < 10; i++) { System.out.println(i); }

const fruits = ["apple", "banana"]; for (let fruit of fruits) { console.log(fruit); } for (let i = 0; i < 10; i++) { console.log(i); }

Java vs JavaScript Comparison