Wojciech Sznapka Web Technologies

Type Hinting is important

2014-06-11

One of my favorite PHP interview questions, is: what is Type Hinting and why it’s important? Putting definition in one sentence, Type Hinting is a way to define type of parameter in function signature and it’s a sine qua non to leverage polymorphism. Because of dynamic typing in PHP, parameters don’t need to have type used. Also, by type here, I mean complex types (class, abstract class, interface, array, closure), not primitives like integer or double.

Immutable value objects in PHP

2014-05-15

Value objects are one of building blocks in Domain Driven Design. They represents a value and does not have an identity. That said, two value objects are equal if their values are equal.

Other important feature is that Value Objects are immutable, i.e. they can not be modified after creation. Only valid way to create Value Object is to pass all required informations to constructor (and should be validated somewhere there). No setter methods should take place.