Question

I want to be able to do something like this:

var MyObject = function(prop) {
  this.property = prop;
};

var stringVar = 'MyObject';

var myObject = new stringVar(1);  // This doesn't work.

assertTrue(myObject.property === 1);

I know that this will work:

var myObject = new window[stringVar](1);

but I was wondering if there was a more context neutral way of accomplishing it.

As a side note: I am obviously trying to avoid using eval().

Answer 1

This is a known limitation in Javascript. There’s no way to reference functions by string in a context-neutral way. What you have is all you can do.

So, if you were to have all this within a closure, it wouldn’t work. Your only option would be to have your constructor as a method of another object:

var constructors = {
    MyObject: function(prop) {
        this.property = prop;
    }
}

var stringVar = 'MyObject';

var myObject = new constructors[stringVar](1);