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Nashorn Syntax Extensions

Nashorn implements ECMAScript 5.1 specification  http://www.ecma-international.org/ecma-262/5.1/

Nashorn implements number of syntactic and API extensions as well. This page describes syntax and API extensions of nashorn implementation.

Function expression closures

...

loadWithNewGlobal({
    script: "foo = 333; print(foo)",
    name: "test"
});

// prints undefined as "foo" is defined in the new global and not here
print(typeof foo); 

exit and quit functions

These synonymous functions exit the current process with specified (optional) exit code.

exit(1); // exit with given exit code
exit();  // exit 0
 
quit(2); // exit with given exit code
quit();  // exit 0

Packages, java, javax, javafx, com, edu

Packages and friends are there to support java package, class access from script. The properties of the Packages variable are all the top-level Java packages, such as java and javax etc.

var Vector = Packages.java.util.Vector;

// but short-cuts defined for important package prefixes like
//  Packages.java, Packages.javax, Packages.com, Packages.edu, Packages.javafx 

var JFrame = javax.swing.JFrame;
var List = java.util.List;