The signature of an operation may indicate a relationship. If the class for an argument of an operation or the return from an operation is a fundamental class such as a String, the relationship typically is not shown on a diagram. For other classes (i.e., nonfundamental classes) the relationship typically is displayed on one or more class diagrams. For example, the two inputs to the setProfessor() operation of the Course class are professor (Professor class) and course offering (CourseOffering class). This implies that relationships exist between:
Course and Professor
Course and CourseOffering
Relationships based on operation signatures initially are modeled as associations that may be refined into dependency ...