What Does J# Mean?

J# is a programming language that provides developers with a set of tools for developing Java applications that can run on Microsoft’s .NET runtime platform.


This term is also known as Visual J# (often pronounced as "Jay-Sharp").

Techopedia Explains J#

The non-Java conventions used in J# make the language friendlier for the .NET environment. Though Java and J# use a common syntax, they differ in that J# uses non-Java conventions to support the .NET Framework. J# has the ability to support Component Object Model (COM) objects and the J/direct interface to Microsoft Windows.

The .NET Framework offers several features that facilitate application development with J#. Some of these features are:

  • The compiler helps to convert Java Language source code to Microsoft Intermediate Language (MSIL).
  • It has class libraries.
  • It has a Java language bytecode converter (for converting bytecode to MSIL), which is very useful when the Java source code is not available.
  • It includes com.ms.lang, com.ms.dll, com.ms.com and com.ms.win32 packages.
  • Its files have the extension .jsl.

The J# compiler offers a wide range of options which can be used with command-line switches:

  • /o: Enable compiler optimization.
  • /debug: Emit debugging information.
  • /help: Display help and description for command-line options.
  • /out: Write compiled output to specified file.

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Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…