Combination and Aggregation

The combination and polymerization have been relatively vague and are now recorded.

"Turn" http://www.blogjava.net/lukangping/archive/2010/08/01/327693.html

Aggregation: Represents a " weak relationship" between the two objects as a whole and a part, and part of the life cycle can transcend the whole. such as a computer and mouse, you can use a shape to indicate:

Combination: Indicates that two objects are " strong relationships" between the whole and the part, and that part of the life cycle cannot go beyond the whole or be absent from the whole. The "part" of a combined relationship cannot be shared across the whole. such as the relationship between human and eye:

The other two more important relationships are associations and dependencies:
Association: It is simple to think that if a class is a property of another class, it must be an association. But you know, aggregation is a special kind of association, and a combination is a special kind of aggregation . The General Association we think is a lateral, not integral part of the relationship, such as a friend relationship.

Dependencies: Temporary relationships between objects, which are temporarily reflected in periods that do not transcend methods. Simply put, in a method used, such as the parameter class, it must be a dependency relationship.

"Multi-use combination, less aggregation"

Combination and Aggregation