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Asked: 2026-05-13T23:41:48+00:00

I’m having a bit of a problem because neither Javascript nor ActiveX (written in

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I’m having a bit of a problem because neither Javascript nor ActiveX (written in C++) are behaving like good little children. All I’m asking them to do is for Javascript to send a byte array and for the ActiveX to receive the byte array correctly in order to do more computation.

This is how I declared my byte array in JS, and I verified it inside JS:

var arr = new Array(0x00, 0xA4, 0x04, 0x00, 0x10,0xA0, 0x00, 00, 00, 0x18, 0x30, 0x03, 0x01, 00, 00, 00, 00, 00, 00, 00, 00);

Javascript sends this array as an argument to an ActiveX method. Here is the tricky part; I want the ActiveX method to receive the byte array as a SAFEARRAY or VARIANT, but I can’t get it to work for the life of me.

I tried debugging and seeing the contents received inside the ActiveX as both SAFEARRAY or VARIANT, but to no avail. Here is the IDL segment:

[id(7), helpstring("blah blah blah")]  HRESULT  Blah( [in] VARIANT blah1, [out, retval]VARIANT* blah2);

Any help is greatly appreciated. Thanks in advance!

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1 Answer

  1. Editorial Team

    Arrays in JScript are no distinct types, they are just objects that have a property length and allow access to their contents via properties.
    In your Invoke()/InvokeEx() method, the VARIANT argument you receive should contain an IDispatch, which represents the scriptable object. On that retrieve the property length and get the contents via the property names 0 to length-1.

    As an implementation example, see e.g. FireBreaths IDispatchAPI::GetProperty() (IDispatchAPI wraps the scriptable browser object there). dispApi->GetProperty("length") would get the size of the array, while dispApi->GetProperty("0") to length-1 would get the actual content of the array.

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