{"componentChunkName":"component---gatsby-theme-teklog-src-templates-post-tsx","path":"/php-7-2-and-object-typehint","result":{"data":{"site":{"siteMetadata":{"siteUrl":"https://blog.tekmi.nl","author":{"name":"Teklog","avatar":"/img/tekmi-icon.svg"}}},"blogPost":{"frontmatter":{"title":"PHP 7.2 and Object Typehint","slug":"php-7-2-and-object-typehint","series":null,"date":"2017-10-29","datePretty":"29 October, 2017","coverImage":{"childImageSharp":{"fixed":{"base64":"data:image/png;base64,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","width":1000,"height":625,"src":"/static/f20334233cd400320dda48dd89d12a97/31987/php_object.png","srcSet":"/static/f20334233cd400320dda48dd89d12a97/31987/php_object.png 1x"}}},"author":null,"authorAvatar":null},"timeToRead":2,"excerpt":"Introduction PHP 7.2 is around the corner.  On the 26th of October 2017, the 5th version of PHP Release Candidate has been announced, which was…","html":"

Introduction

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PHP 7.2 is around the corner.  On the 26th of October 2017, the 5th version of PHP Release Candidate has been announced, which was preceded by 3 alpha, 3 beta and 4 RC versions. First alpha version was announced on the 8th of June 2017 and the final version is about to be released by the end of November 2017.

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If you are impatient and curious as I am, it's right time to take a sneak peak at what PHP team is cooking for us. You can track all implemented features by studying PHP Request For Comments wiki page.

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Without further ado, let's explore the first feature together, an amazing Object Typehint

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Assumptions

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Try it yourself

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Clone blogging-phplatest repository

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git clone https://github.com/tekmi/blogging-phplatest\ncd blogging-phplatest
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Run docker container, based on the php 7.2.0 RC5 image.

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docker run -it --rm \\\n-v \"$PWD\":/usr/src/php-7.2 \\\n-w /usr/src/php-7.2 \\\nphp:7.2.0RC5-cli-stretch \\\nphp php-7.2/object_typehint/index.php
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Update Dec 2017: If you experience problems with image php:7.2.0RC5-cli-stretch, try php:7.2.0-cli-stretch instead.

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Explanation

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PHP 7.0 introduced scalar types for parameters as well as return types. PHP 7.1 on top of this added Nullable types, however there was still not possible to typehint objects.

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PHP 7.2 for the rescue - it will soon be possible to use new object typehint as shown below:

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function moves(object $obj): string\n{\n  return get_class($obj);\n}
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If you pass string, null or anything else that is not an object, you will encounter fatal error similar to: Fatal error: Uncaught TypeError: Argument 1 passed to moves() must be an object, string given

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On the other hand, if you pass valid objects, as presented below, everything will work like a charm.

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moves(json_decode('{}'))\nmoves(new \\stdClass())\nmoves(new class() {})
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How did we do it until now

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Most probably parameter $obj won't be type-hinted (if we intend to accept scalars and objects) and we should check for an object - otherwise get_class would fire: Warning: get_class() expects parameter 1 to be object, string given

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function moves($obj): string\n{\n  return is_object($obj) ? get_class($obj) : '';\n}
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Summary

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By using object typehint, code should be easier to understand and errors detected quicker. It's a great addition to PHP language which I'm awaiting with impatience.

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