Re: Local constants

> On Sep 4, 2024, at 16:45, Rob Landers <rob@bottled.codes> wrote: > > I think, conceptually, this makes sense, but maybe I'm the only one who writes > > $arr = doSomething(); > $arr = array_map(fn($x) => $x->prop, $arr); > $arr = array_filter($arr, $filterFunc); > > instead of > > $arr = array_filter(array_map(fn($x) => $x->prop, doSomething()), $filterFunc); IMO, that's a failing of PHP not supporting object syntax (and reasonable api) for non-object values. In other languages, I can write code such as: let arr = doSomething() .map { $0.prop } .filter(filterFunc) Which is more readable than both PHP versions. > And I feel like having constant variables would result in more of the latter, which I feel is > more unreadable. Though I do note that my opinion of what is readable might be different from other > people's. > > That being said, I would much rather see block-scoped variables than local variables via let or > var or something: > > var $aNumber = 12; > > foreach($arr as var $item) { > echo $item; // item exists here > } > > echo $item; // item doesn't exist here > > PHP is simply too verbose to really benefit from local constants, but would benefit from > block-scope far more. For example, with local constants, you couldn't write that foreach > because that variable exists in the scope of the function and can only be defined once. > > — Rob I'd suggest that the foreach could be written with either of let/var to both locally scope $item, which would explicitly disallow/allow $item to be changed while in the loop. Another benefit of local constants is preventing accidentally reusing a prior variable. For example, if I set a temporary variable to something, and then later in the function, reuse that same name for a new temporary but don't set the value on all flow paths, then the value from earlier in the function leaks through, whereas either using a constant, or a second explicit variable definition would have exposed and/or prevented the issue. -John