Constructor invocation without parentheses [duplicate]

Is there any difference between

var obj1 = new Constructor;

and

var obj2 = new Constructor();

given that Constructor is a constructor function?

What happens when a method is accessed without the () parentheses?

When we call a function with parentheses, the function gets execute and returns the result to the callable. In another case, when we call a function without parentheses, a function reference is sent to the callable rather than executing the function itself.

Why do some methods not have parentheses?

Without parentheses you're not actually calling the function. A function name without the parentheses is a reference to the function. We don't use the parentheses in that code because we don't want the function to be called at the point where that code is encountered.

According to the MDN docs: