Cardinality Constraints

Let’s learn about cardinality constraints.

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Cardinality constraints in UML
Cardinality constraints in various languages
Example

A cardinality constraint requires that the cardinality of a multi-valued property’s value set is not less than a given minimum cardinality or not greater than a given maximum cardinality.

Cardinality constraints in UML

In UML, cardinality constraints are called multiplicity constraints, and minimum and maximum cardinalities are expressed with the lower bound and upper bound of the multiplicity expression. This is shown in the following diagram, which contains two examples of properties with cardinality constraints.

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Introduction

The Foundations of Web Apps

Javascript Fundamentals

Building a Minimal Web App with Plain JS in Seven Steps

Integrity Constraints and Data Validation

Constraint Validation in Plain JS

Enumerations

Enumeration Attributes in Plain JS

Reference Properties and Unidirectional Associations

Implementing Unidirectional Functional Associations

Implementing Unidirectional Non-Functional Associations

Bidirectional Associations

Implementing Bidirectional Associations

Subtyping and Inheritance

Subtyping with Plain JS

Conclusion

Cardinality Constraints

Cardinality constraints in UML