Domain Driven Design Value Object Example

Now you know what entity is and what value object in ddd is.

Domain driven design value object example. However hopefully this is the first step towards a better understand of domain driven design in general. That is unlike an entity which has a unique identifier and remains distinct even if its properties are otherwise identical two value objects with the exact same properties can be considered equal value objects are a pattern first described in evans domain driven design book and further. If customer is an entity object then one instance of this object representing a specific bank client cannot be reused for account operations corresponding to other clients.

Value object are often the child object in the. Two important building blocks when we talk about code are entities and value objects. In domain driven design entities and value objects can exist independently.

For those who aren t familiar there is a concept in domain driven design that distinguishes between objects with identity entities and those without value objects. Suppose you have two employee objects in your system i e. When we model the domain we typically think in terms of entities which are then persisted and modified over time.

Check out his book on the subject. A window can only be defined if there is a room. Collaboration between technical and domain experts.

Entities when two objects are deemed equal on the basis of their identity they are considered entities. Value type object belongs to an entity type object. A value object is an immutable type that is distinguishable only by the state of its properties.

A value object is an important concept in domain driven design ddd. An order note can only exist if an order is placed. The lifespan of a value type instance is bounded by the lifespan of the owning entity instance.