Components All New MacOS Windows Linux iOS
Examples Mac & Win Server Client Guides Statistic FMM Blog Deprecated Old


Creates a new JavaScript engine instance.

Component Version macOS Windows Linux Server iOS SDK
JavaScript 10.0 ✅ Yes ✅ Yes ✅ Yes ✅ Yes ✅ Yes
MBS( "JS.New" { ; JSRef } )   More


Parameter Description Example Flags
JSRef The desired js reference.
Usually each one gets a number assigned, but you can create a JavaScript environment with a fixed name, so you can anywhere reference it by name.
"JS" Optional


Returns JS reference number or error.


Creates a new JavaScript engine instance.
This object contains all the functions and properties you defined.
Please release the object later with the JS.Release function.

Your own JavaScript engine is useful for:
  • Running some snippet of JavaScript code without web viewer.
  • Using various JavaScript libraries
  • Providing a scripting language to your own solution.
  • Doing JavaScript on server side.
  • Working with JSON data
  • Enjoy using regular expressions, unicode text functions, number parsing and formatting with no platform dependencies

If JSRef is "js", we use this one as the global JavaScript engine for custom functions and JS.CF function. See our example JavaScript Custom Functions.

When using a name for the reference number, you can use this reference anywhere you need to pass a JavaScript reference number.

Check also our JavaScriptWebKit functions for using WebKit’s JavaScript engine on macOS and iOS.


Evaluate a bit of JavaScript:

Set Variable [ $js ; Value: MBS( "JS.New" ) ]
Set Variable [ $r ; Value: MBS( "JS.Evaluate"; $js; "4+5") ]
Show Custom Dialog [ "Result" ; $r ]
Set Variable [ $r ; Value: MBS( "JS.Release"; $JS ) ]

Create named JavaScript Environment:

Set Variable [$js; MBS( "JS.New"; "js" ) ]

See also

Release notes

  • Version 11.3
    • Added parameter for JS.New function to define the identifier used for the new instance.

Example Databases

Blog Entries

This function checks for a license.

Created 7th December 2019, last changed 9th February 2023

JS.List - JS.Now