By using the self keyword, we don't The Value Objects are a fundamental building block of Domain-Driven Design, and they're used to model concepts of your Ubiquitous Language in code. A Value Object is not just a thing in your Domain — it measures, quantifies, or describes something. Value Objects can be seen as small, simple objects — such as money or a date range — whose equality is not based on identity, but instead on the content held.
For example, a product price could be modeled using a Value Object. In this case, it's not representing a thing, but rather a value that allows us to measure how much Money a product is worth. The memory footprint for these objects is trivial to determine (calculated by their constituent parts) and there's very little overhead. As a result, new instance creation is favored over reference reuse, even when being used to represent...
