oop

  • An enum can implement an interface but cannot extend

    Enums are final, cannot extend anything and cannot be extended, which removes a set of designs that class constants had allowed. Implementing an interface is what makes an…

  • readonly locks on first write, not at construction

    A readonly property is not initialised-at-declaration; it is write-once from inside the declaring class, and the difference decides what a wither method can do. The property has no…

  • never is not void, and the analyser knows

    void means the function returns nothing and never means it does not return, and the second is information a static analyser can act on. The practical value is…

  • Enums, and the string column that was pretending

    8.1 on 25 November, and the feature PHP had been simulating with class constants for a decade. A status column holding three spellings of the same thing.

  • Serialising an object with readonly properties

    unserialize creates an object without calling the constructor and then writes the properties, which is precisely the thing readonly forbids. Native serialisation is allowed by an explicit carve-out…

  • from() throws and tryFrom() returns null

    Hydrating an enum from a request parameter with from() produced an uncaught ValueError on the first malformed input, which was about nine minutes after deploy. The two methods…

  • __set on a class that declares the property does nothing

    __set is only called for inaccessible or undefined properties, so declaring the property you meant to intercept disables the magic silently. The private case is the one that…

  • new in initializers, and the default that is an object

    A constructor with an optional dependency needed a null default and a line of null-coalescing, in every class that had one. The exclusion of property defaults is the…

  • Readonly properties and the value object that stops defending itself

    8.1, and a keyword that removes a getter per property. Forty value objects, each with private fields and public accessors that existed only to prevent writes.

  • First-class callable syntax replaces four spellings

    A callable could be written four ways, all of them strings or arrays that no tool could follow through a rename. The literal … is not a placeholder…