When does the number of references to an object instance increase in a program?

The increase in the retain count of an object instance in a program occurs each time a new strong reference to that object is created. In the context of iOS and Objective-C, this happens, for example, when:

• You assign the object to a new strong variable.
• You pass the object to a method that retains a strong reference.
• You add the object to a collection (such as an array or dictionary) that holds strong references.

This is important for managing the object's lifetime: the object will exist as long as there is at least one strong reference to it.