--- title: Generic arrays in PHP | daily.dev description: Explores two approaches to emulate generics in PHP using ArrayObject: one that subclasses ArrayObject with type-hinted method overrides for a single class... canonical: https://daily.dev/posts/generic-arrays-in-php-ca5usu1go twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Generic arrays in PHP | daily.dev og:description: Explores two approaches to emulate generics in PHP using ArrayObject: one that subclasses ArrayObject with type-hinted method overrides for a single class... og:url: https://daily.dev/posts/generic-arrays-in-php-ca5usu1go og:image: https://api.daily.dev/og/posts/ca5Usu1go.png og:image:alt: Generic arrays in PHP og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Generic arrays in PHP **[Maarten Balliauw](https://daily.dev/sources/maartenballiauw)** · 3 min read · 0 upvotes · 0 comments ## Summary Explores two approaches to emulate generics in PHP using ArrayObject: one that subclasses ArrayObject with type-hinted method overrides for a single class type, and a more flexible GenericArrayObject that accepts a validation callback (like is_string or a custom function) to enforce type constraints on array elements at runtime, throwing exceptions on violations. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How can I create a type-safe array in PHP since PHP doesn't support generics? Subclass PHP's ArrayObject and override the append() and offsetSet() methods with type hints restricting the accepted value type. Calling append() or offsetSet() with a mismatched type throws an exception automatically, giving basic compile-time-like safety for a single object type without needing true generics support. _daily.dev surfaces practical PHP patterns like this for developers working around language limitations._ ### How do I enforce a primitive type constraint like string-only values in a PHP ArrayObject? Create a GenericArrayObject subclass that stores a validation function name (such as is_string or is_int) and calls it via call_user_func_array inside overridden append() and offsetSet() methods, throwing an exception if validation fails. This works for primitives and custom checks, like a regex validator for email-formatted strings, unlike simple type hinting which only works for object types. _Developers building type-safe PHP data structures can track such workaround patterns on daily.dev._ ## Similar posts on daily.dev - [CakePHP is now fully generics-able – DerEuroMark](https://daily.dev/posts/cakephp-is-now-fully-generics-able-dereuromark-cwz39vwo6) · DerEuroMark · 3 upvotes · 0 comments - [Constrain your classes with PHPStan](https://daily.dev/posts/constrain-your-classes-with-phpstan-s6dcepwbf) · hbgl · 2 upvotes · 0 comments - [\[RFC\] \[Discussion\] Bound-Erased Generic Types](https://daily.dev/posts/rfc-discussion-bound-erased-generic-types-ze8fx3ymf) · externals.io · 0 upvotes · 0 comments - [Class Extension](https://daily.dev/posts/class-extension-d68x8djfe) · externals.io · 0 upvotes · 0 comments - [\[Pre-RFC\] Scalar object methods \(with a working implementation\)](https://daily.dev/posts/pre-rfc-scalar-object-methods-with-a-working-implementation--j65oyhuep) · externals.io · 0 upvotes · 0 comments --- Tags: [#general-programming](https://daily.dev/tags/general-programming), [#php](https://daily.dev/tags/php) [View this post on daily.dev](https://daily.dev/posts/generic-arrays-in-php-ca5usu1go) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Generic arrays in PHP","url":"https://daily.dev/posts/generic-arrays-in-php-ca5usu1go","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/generic-arrays-in-php-ca5usu1go"},"datePublished":"2026-10-04T13:06:36.058Z","dateModified":"2026-10-04T13:09:49.606Z","description":"Explores two approaches to emulate generics in PHP using ArrayObject: one that subclasses ArrayObject with type-hinted method overrides for a single class...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/6fe05d605f41f96e642c727bdcdc49d7?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/6fe05d605f41f96e642c727bdcdc49d7?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Maarten Balliauw","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Maarten Balliauw","logo":"https://media.daily.dev/image/upload/s--rOTg3VYO--/f_auto,q_auto/v1791119043/logos/maartenballiauw?_a=BAMAMicg0","url":"https://daily.dev/sources/maartenballiauw"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/generic-arrays-in-php-ca5usu1go","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"general-programming,php","timeRequired":"PT3M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Maarten Balliauw","item":"https://daily.dev/sources/maartenballiauw"},{"@type":"ListItem","position":3,"name":"Generic arrays in PHP"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/generic-arrays-in-php-ca5usu1go#faq","mainEntity":[{"@type":"Question","name":"How can I create a type-safe array in PHP since PHP doesn't support generics?","acceptedAnswer":{"@type":"Answer","text":"Subclass PHP's ArrayObject and override the append() and offsetSet() methods with type hints restricting the accepted value type. 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