What's New in PHP 7.4?

PHP is constantly evolving and getting better and faster. Come learn about the latest features in the language from the past few years and what's coming up very soon in version 7.4.

Transcript

1. What's New
   In PHP 7.4?
   

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2. Hello!
   I am Jeremy Lindblom
   Longtime PHP lover and co-organizer of azPHP
   You can find me at @jeremeamia
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3. “
   I did not develop the PHP we
   know today. Dozens, if not
   hundreds of people, developed
   PHP. I was simply the first
   developer.
   —  R A S M U S   L E R D O R F  —
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4. Thank You
   Nikita Popov
   nikic is an exceptional
   programmer, and has
   been responsible for so
   many of PHP’s recent
   improvements, both in
   performance & syntax.
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5. Let’s Review
   Let’s start by remembering features
   that were added in PHP 7.2 and 7.3
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6. PHP 7.2
   ◦ object type
   ◦ libsodium
   ◦ Limited variance
   ◦ Trailing comma (use)
   ◦ Argon2 hash alg
   ◦ New Multibyte funcs
   ◦ Zip ext enhancements
   Recent Additions
   PHP 7.3
   ◦ Improved here/nowdoc syntax
   ◦ Trailing comma (params)
   ◦ Destructuring with references
   ◦ Multibyte improvements
   ◦ array_key_first/last()
   ◦ JSON_THROW_ON_ERROR
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7. What’s New?
   Let’s take a look at some of the new
   features coming next month in PHP 7.4
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8. 1.
   Typed Properties
   Can we type everything now? I think so!
   

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9. Typed Properties
   class Model {
   private array $data;
   private bool $loaded;
   private string $name;
   }
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10. What Types Can I Use?
    array
    int
    string
    bool
    float
    object
    10
    iterable
    
    
    ?
    callable
    void
    

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11. 2.
    Improved Covariance
    and Contravariance
    Yay! Factories with generic return types!
    

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12. Limited Return Type Covariance
    interface Client {...}
    class MyClient implements Client {...}
    abstract class ClientFactory {
    abstract protected function create(): Client;
    }
    class MyClientFactory extends ClientFactory {
    protected function create(): MyClient {...}
    }
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13. Contravariance in Parameters
    class Mapper {
    public function map(Iterator $i) {...}
    }
    class ArrayMapper extends Mapper {
    public function map(iterable $iter) {
    return parent::map(iterator_for($iter));
    }
    }
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14. 3.
    Preloading
    Preloading frameworks into opcache? Nice!
    

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15. Preloading
    ◦ Part of Opcache
    ◦ Write a PHP script to preload files
    ◦ Executed once on server startup
    ◦ All preloaded files are available in memory
    for ALL requests
    ◦ Changes made to the source file won't have
    any effect, until the server is restarted
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16. Preloading
    # In your INI
    opcache.preload=/path/to/preload.php
    # In your preload.php
    $files = /* files to preload */;
    foreach ($files as $file) {
    opcache_compile_file($file);
    }
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17. 4.
    Unpacking in Arrays
    Making arrays that much more sweet.
    

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18. Unpacking Arrays
    $data = ['b', 'c', 'd'];
    $more = ['a', …$data, 'e', 'f'];
    # Works with Iterators too
    $other = ['a', …$iterator, 'e'];
    # But not with Associative Arrays
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19. Goodbye iterator_to_array();
    # These two lines do the same thing
    $array = iterator_to_array($iter);
    $array = […$iter];
    # Again, it doesn’t work with
    # associative arrays.
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20. 5.
    Arrow Functions
    (Short Closures)
    One-liner array_maps are easy on the eyes.
    

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21. Arrow Functions / Short Closures
    $add = 5;
    # Before
    array_map(function($num) use ($add) {
    return $num + $add;
    });
    # After
    array_map(fn($num) => $num + $add, $numbers);
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22. 6.
    Null Coalescing
    Assignment
    More weapons in the war against NULL.
    

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23. Null Coalescing Operator
    // Way Before
    $params['greet'] = isset($params['greet'])
    ? $params['greet']
    : 'hello';
    // Before
    $params['greet'] = $params['greet'] ?? 'hello';
    // After
    $params['greet'] ??= 'hello';
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24. 7.
    Weak References
    For more intentional memory optimizations.
    

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25. Weak References
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26. Weak References
    $obj = new Thing();
    $ref = new WeakRef($obj);
    // Later
    if ($ref->valid()) {
    $myObj = $ref->get();
    } else {
    throw new Exception('object destroyed');
    }
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27. 8.
    Numeric Literal
    Separator
    Better readability for funky numbers.
    

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28. Numeric Literal Separator
    $dec = 299_792_458;
    $hex = 0xFFFF_A974;
    $bin = 0b0101_1111;
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29. 9.
    Exceptions in toString
    Thank you. Thank you. Thank you. Thank you.
    

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30. Exceptions in __toString
    class URL {
    // …
    public function __toString()
    {
    throw new Exception('YOLO!');
    }
    }
    // NOT A FATAL ERROR ANYMORE!
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31. 10.
    New Custom
    Serialization Methods
    Do we finally have good/safe serialization?
    

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32. New Serialization
    ◦ Old way:
    ◦ __sleep() and __wakeup() methods
    ◦ Serializable interface
    ◦ New __serialize() and __unserialize()
    ◦ Addresses issues with previous implementations
    ◦ Serializable interface will be deprecated
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33. New Custom Serialization Methods
    class Foo {
    private $bar;
    public function __serialize(): array {
    return ['bar' => $this->bar];
    }
    public function __unserialize(array $data) {
    $this->bar = $data['bar'];
    }
    }
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34. 34
    Thanks!
    Any questions?
    You can find me at:
    ◦ @jeremeamia
    ◦ azPHP Meetups
    

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35. Credits
    Special thanks to all the people who made and
    released these awesome resources for free:
    ◦ Presentation template by SlidesCarnival
    ◦ Photographs by Unsplash
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36. Resources
    ◦ https://www.php.net/manual/en/migration74.new-features.php
    ◦ https://stitcher.io/blog/new-in-php-74
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