How to SetValue with array properly?

[sea0920]

I thought I had to set ArrayInstance when I use SetValue.
But it seems like I have to put object[]?
Otherwise, I cannot use push() method.

class Program
    {
        static void Main(string[] args)
        {
            var engine = new Jint.Engine(cfg => cfg.AllowClr());

            var dict = new Dictionary<uint, Jint.Runtime.Descriptors.PropertyDescriptor>();
            dict.Add(0, new Jint.Runtime.Descriptors.PropertyDescriptor(1, true, true, true));
            dict.Add(1, new Jint.Runtime.Descriptors.PropertyDescriptor(2, true, true, true));
            var myArr = new ArrayInstance(engine, dict);
            engine.SetValue("myArr", myArr); // myArr.push(3) works when I change myArr to myArr.ToObject()
            engine.Execute("myArr.push(3); System.Console.WriteLine(myArr[2]);");
        }
    }

[lahma]

So what are you trying to achieve? Do you want to fill the array on c# side or what's this use case. It should be enough just to create and array of objects like new object[] { 123, "hello world" } and give that to SetValue. I hope you are using v3 beta, so we are talking about the same API.

[sea0920]

I am using v3 beta. I am not clear why we need a class like ArrayInstance. Is it something used internally and Jint users don't need to know? Does the array of objects new object[] { 123, "hello world" } turn into ArrayInstance when we SetValue?

[lahma]

ArrayInstance generally is used by Jint during runtime, but it's also available to C# when needed. The example array should turn into ArrayInstance when used with SetValue, all elements in array also go through the JsValue conversion during the process. After that the array inside the engine "native-like".