What is aggregation and example?

1 : a group, body, or mass composed of many distinct parts or individuals A galaxy is an aggregation of stars and gas. 2a : the collecting of units or parts into a mass or whole.

Association refers to “has a” relationship between two classes which use each other. Aggregation refers to “has a”+ relationship between two classes where one contains the collection of other class objects.

Aggregation is the process of combining things . That is, putting those things together so that we can refer to them collectively. As an example, think about the phone numbers on your cell phone. You can refer to them individually – your mother’s number, your best friend’s number, etc.