OOP Newbie: Accessing Fields Directly vs. Passing Objects as Parameters

Question

Suppose Object1 needs information from Object2. I'll say it's in an Object2 property, but the info could as easily be the return value from an Object2 function. When I look at others' code I see sometimes they will have a method in Object1 directly accessing the property. Other times I see people pass Object2 as a parameter in a method, and then access the property from the passed Object2.

These scenarios seem almost the same to me. Directly accessing the property seems simpler. As a newbie, what do you think I should think about when deciding how Object1 should get information from Object2? (When would I want to have an object parameter rather than directly accessing the property?)

Thanks -- Al C.

Answer 1

One problem with passing Object2 to Object1 is that you create a dependency between Object2 and Object1. The only way that Object1 can obtain the data it needs is to have a reference to Object2.

Now, sometimes you want that, but most of the time you don't. So you're most likely better off simply passing the value you need as a parameter to the method, rather than passing the instance of Object2.