How can one know if a property is an array?

Question

Hi there,

I am calling a JavaScript function using the rhino API:

Function fct = context.compileFunction(scope, script, "script", 1, null);
Scriptable result = (Scriptable) fct.call(
            context, scope, attrs, new Object[0]);
Object obj = result.get("objectClass", result);

Now, how can I test if the value of the "objectClass" property is an array?

Answer 1

You can check if any object is an array by doing object.getClass().isArray()

Answer 2

boolean b = object.getClass().isArray(); if (b) { // object is an array }

Above solution is for checking JAVA arrays.

If you are looking for javascript arrays in JAVA code, Then you need to know what object is returned by JAVASCRIPT for Array and check using "instanceof".

Answer 3

This might give you some idea: Declare a function to determine whether an object is an array and call that function passing your object.

engine.eval("function isArray(obj) {" +
                "  return obj.constructor == Array;" +
                "}");
Object obj = engine.eval("[1,2,3,4]");
Invocable invocableEngine = (Invocable) engine;
System.out.println(invocableEngine.invokeFunction("isArray", obj)); //true