Execute JScript code stored as a string and pass arguments

Question

So I've read Execute JavaScript code stored as a string and looked at this simple answer.

My question, what if the JScript code, stored in the string, expects arguments? how to I pass it?

First try:

var jsStr = "WScript.Echo(WScript.Arguments[0]);";
eval(jsStr);

Second try:

var F = new Function(jsStr);
F.call(this,'test str');

But this poor attempt failed.

Note:

Let's assume the I have no control on jsStr value. So basically, reformatting it is out of the question at this moment.

Answer 1

The problem is caused by the []. WScript.Arguments is an object (provided by the script host runtime), but not an array. To access its elements, you have to use (), i.e. call its Item() function. Evidence:

var jsStr;
jsStr = "WScript.Echo('a', WScript.Arguments(0));"; eval(jsStr);
jsStr = "WScript.Echo('b', WScript.Arguments.Item(0));"; eval(jsStr);

var expr;
expr = "typeof WScript.Arguments"; WScript.Echo(0, expr, eval(expr));
expr = "typeof WScript.Arguments(0)"; WScript.Echo(1, expr, eval(expr));
expr = "typeof WScript.Arguments[0]"; WScript.Echo(2, expr, eval(expr));

output:

cscript 27250366.js pipapo
a pipapo
b pipapo
0 typeof WScript.Arguments object
1 typeof WScript.Arguments(0) string
2 typeof WScript.Arguments[0] undefined