Cogway https://cogway.dev/ Interactive explainers for Laravel and PHP. One concept at a time, turned into something you can step through, break, and run again. en Tue, 15 Sep 2026 00:00:00 GMT Why strlen and mb_strlen disagree about one string https://cogway.dev/explainers/bytes-vs-characters/ https://cogway.dev/explainers/bytes-vs-characters/ A PHP string is a row of bytes, not a row of characters. strlen counts bytes, mb_strlen counts code points, and grapheme_strlen counts what a reader can see. Cutting with the wrong one breaks the text in two different ways. Tue, 15 Sep 2026 00:00:00 GMT Why chunking can skip half your rows https://cogway.dev/explainers/chunk-skips-rows/ https://cogway.dev/explainers/chunk-skips-rows/ chunk() pages with LIMIT and OFFSET and re-runs the query each time. Write to the column you filtered on and rows shift out from under it, so the next offset starts past rows nobody ever visited. Tue, 15 Sep 2026 00:00:00 GMT Catastrophic backtracking: when one regex melts a CPU https://cogway.dev/explainers/catastrophic-backtracking/ https://cogway.dev/explainers/catastrophic-backtracking/ A nested quantifier makes the number of paths double with every letter, and it is the failing input that is slow. PHP gives up and returns false. Wed, 05 Aug 2026 00:00:00 GMT Magic methods: how $user->name works when there is no name https://cogway.dev/explainers/magic-methods/ https://cogway.dev/explainers/magic-methods/ Magic methods do not run first. A declared, accessible member always wins, and __get and __call are only the fallback when ordinary lookup finds nothing. Wed, 05 Aug 2026 00:00:00 GMT The middleware pipeline, and where the response comes back through https://cogway.dev/explainers/middleware-pipeline/ https://cogway.dev/explainers/middleware-pipeline/ Middleware is not a list of filters run once on the way in. Each one wraps the request and the response, so the after halves run in reverse. Wed, 05 Aug 2026 00:00:00 GMT Sanctum: a token or a cookie, depending on who is calling https://cogway.dev/explainers/sanctum-token-vs-session/ https://cogway.dev/explainers/sanctum-token-vs-session/ Sanctum authenticates two callers behind one guard: your own SPA by session cookie, a mobile client by bearer token. A token in your own SPA is the mistake. Wed, 05 Aug 2026 00:00:00 GMT How Eloquent casts raw database values into objects https://cogway.dev/explainers/attribute-casting/ https://cogway.dev/explainers/attribute-casting/ Model columns are not typed properties. They live in an array of raw values, and $casts converts them on read. isDirty compares them cast, not only raw. Tue, 04 Aug 2026 00:00:00 GMT The cache stampede, and what a lock prevents https://cogway.dev/explainers/cache-stampede/ https://cogway.dev/explainers/cache-stampede/ Cache::remember protects the database only while the value is warm. When a key expires, every concurrent request runs the callback. A lock collapses it to one. Tue, 04 Aug 2026 00:00:00 GMT When PHP copies a value, and when it shares it https://cogway.dev/explainers/references-memory/ https://cogway.dev/explainers/references-memory/ PHP assigns arrays by value, but defers the copy until a write. A reference is the opposite: two names, one slot. Copy-on-write and the foreach trap follow. Sun, 02 Aug 2026 00:00:00 GMT What a nested transaction actually rolls back https://cogway.dev/explainers/transaction-rollback/ https://cogway.dev/explainers/transaction-rollback/ A nested DB::transaction is a savepoint, not its own transaction. An inner commit runs no SQL, and nothing is durable until the outermost commit. Sun, 02 Aug 2026 00:00:00 GMT Why a projection is a view, not the source of truth https://cogway.dev/explainers/event-sourcing/ https://cogway.dev/explainers/event-sourcing/ A projection is one of many views folded from the event stream. Add a projector after the fact, replay it, and it rebuilds from events that already existed. Sat, 01 Aug 2026 00:00:00 GMT Why eager loading changes the number of queries https://cogway.dev/explainers/n-plus-one/ https://cogway.dev/explainers/n-plus-one/ with() is not an optimisation you sprinkle on. It changes when your queries happen. Drive the loop and watch the counter. Sat, 01 Aug 2026 00:00:00 GMT Why a failed job does not go straight to failed_jobs https://cogway.dev/explainers/queue-retries/ https://cogway.dev/explainers/queue-retries/ A thrown job is released and retried after a backoff. $tries counts total attempts, not retries. Killing the worker does not fail the job. Sat, 01 Aug 2026 00:00:00 GMT Why == and === are not the same comparison https://cogway.dev/explainers/type-juggling/ https://cogway.dev/explainers/type-juggling/ PHP's == does not compare values by eye. It coerces both sides to a common type first, following fixed rules, and one of those rules changed in PHP 8. Sat, 01 Aug 2026 00:00:00 GMT