New features of PHP 7

anonymous-class.php

<?php

define('PLAYERS', [
  '1' => ['Garry Kasparov', 2851],
  '2' => ['Anatoly Karpov', 2780],
  '3' => ['Magnus Carlsen', 2882],
  '4' => ['Bobby Fischer',  2785]
]);

interface PlayerDetailsInterface 
{
  public function getName();
  public function getRanking();
}

/**
 * Get Chess player detail
 * 
 * @return PlayerDetailsInterface
 */
function getChessPlayerDetails($id): PlayerDetailsInterface
{
  // Do some processing, consult some internet DB, Webservice or another resource
  $player = PLAYERS[$id];
  $name = $player[0];
  $ranking = $player[1];
  
  return new class($name, $ranking) implements PlayerDetailsInterface
  {
    private $name;
    private $ranking;
    
    public function __construct($name, $ranking) 
    {
      $this->name = $name;
      $this->ranking = $ranking;
    }
    
    public function getName() 
    {
      return $this->name;
    }
    
    public function getRanking() 
    {
      return $this->ranking;
    }
  };
}

foreach (array_keys(PLAYERS) as $id) {
  /**@var PlayerDetailsInterface $detail */
  $detail = getChessPlayerDetails($id);
  echo $detail->getName(), ': ', $detail->getRanking(), PHP_EOL;
}

/* Print
Garry Kasparov: 2851
Anatoly Karpov: 2780
Magnus Carlsen: 2882
Bobby Fischer: 2785
*/

constant-array.php

<?php
define('DAYS', [
  'sun' => 'Sunday',
  'mon' => 'Monday',
  'tue' => 'Tuesday',
  'wed' => 'Wednesday',
  'thu' => 'Thursday',
  'fri' => 'Friday',
  'sat' => 'Saturday'
]);

// PrSunday
echo DAYS['sun'], PHP_EOL;

generator-delegate.php

<?php
function gen()
{
    yield 1;
    yield 2;
    yield from gen2();
}

function gen2()
{
    yield 3;
    yield 4;
}

foreach (gen() as $val)
{
    echo $val, PHP_EOL;
}

// Print
// 1
// 2
// 3
// 4

generator-return.php

<?php

$gen = (function() {
    yield 1;
    yield 2;

    return 3;
})();

foreach ($gen as $val) {
    echo $val, PHP_EOL;
}

echo $gen->getReturn(), PHP_EOL;

// Print
// 1
// 2
// 3

null-coalescing-operator-chained.php

<?php
$username = $_GET['user'] ?? $_POST['user'] ?? 'nobody';

null-coalescing-operator.php

<?php
// Fetches the value of $_GET['user'] and returns 'nobody' if it does not exist.
$username = $_GET['user'] ?? 'nobody';

// This is equivalent to:
$username = isset($_GET['user']) ? $_GET['user'] : 'nobody';

null-coalescing-or.php

#!/bin/bash
# Print yes
perl -e '$a = $b || "yes"; print($a);'

# Print yes
php -r '$a = $b ?? "yes"; print_r($a);'

# Print yes
perl -e '$a = 0 || "yes"; print($a);'

# Print 0
php -r '$a = 0 ?? "yes"; print_r($a);'

# Print I have a value
perl -e '$a = "I have a value" || "yes"; print($a);'

# Print I have a value
php -r '$a = "I have a value" ?? "yes"; print_r($a);'

params-types-strict.php

<?php
declare(strict_types = 1);

function test_param(int $a, bool $is_ready, string $str) {
    echo $a, ' => ', gettype($a), "\n";
    echo $is_ready, ' => ', gettype($is_ready), "\n";
    echo $str, ' => ', gettype($str), "\n";
}

class Test {
    public function __toString() {
        return Test::class;
    }
}

test_param(5, true, new Test());

// Print
// Fatal error: Uncaught TypeError: Argument 3 passed to test_param()
// must be of the type string, object given...

params-types.php

<?php
function test_param(int $a, bool $is_ready, string $str) {
    echo $a, ' => ', gettype($a), "\n";
    echo $is_ready, ' => ', gettype($is_ready), "\n";
    echo $str, ' => ', gettype($str), "\n";
}

class Test {
    public function __toString() {
        return Test::class;
    }
}

test_param(5.5, true, new Test());

// Print
// 5 => integer
// 1 => boolean
// Test => string

return-type-declarations.php

<?php
function sum($a, $b): int {
    return $a + $b;
}

function sum_f($a, $b): float {
    return $a + $b;
}

class Test {
    public function __toString() {
        return __CLASS__;
    }
}

function return_str(): string {
    return (new Test());
}

// Print 5
echo sum(3.5, 2), PHP_EOL;

// Print 5.5
echo sum_f(3.5, 2), PHP_EOL;

// Print Test
echo return_str(), PHP_EOL;

return-type-strict-declarations.php

<?php
declare(strict_types=1);

function sum($a, $b): int {
    return $a + $b;
}

function sum_f($a, $b): float {
    return $a + $b;
}

class Test {
    public function __toString() {
        return __CLASS__;
    }
}

function return_str(): string {
    return (new Test());
}

// Print
// Fatal error: Uncaught TypeError: Return value of sum() must be of the type
// integer, float returned...
echo sum(3.5, 2), PHP_EOL;

// Print 5.5
echo sum_f(3.5, 2), PHP_EOL;

// Print
// Fatal error: Uncaught TypeError: Return value of return_str() must be of the
// type string, object returned...
echo return_str(), PHP_EOL;

spaceship.php

<?php
echo 1 <=> 1; //  0
echo 1 <=> 2; // -1
echo 2 <=> 1; //  1

echo 1.5 <=> 1.5; //  0
echo 1.5 <=> 2.5; // -1
echo 2.5 <=> 1.5; //  1
 
echo "a" <=> "a"; //  0
echo "a" <=> "b"; // -1
echo "b" <=> "a"; //  1

use-constants.php

<?php
namespace Config {
  const DB_DRIVER = 'mysql';
  const DB_HOST   = 'localhost';
  const DB_PORT   = '3306';
  const DB_USER   = 'root';
}

// Global namespace
namespace {
  // Before/Antes PHP 7
  // use const Config\DB_DRIVER;
  // use const Config\DB_HOST;
  // use const Config\DB_PORT;
  // use const Config\DB_USER;

  // PHP 7
  use const Config\{DB_DRIVER, DB_HOST, DB_PORT, DB_USER};

  echo 'Connection details', PHP_EOL;
  echo 'Driver: ', DB_DRIVER, ', Host: ', DB_HOST, ', Port: ', DB_PORT, ', user: ', DB_USER, PHP_EOL;
}

use-functions.php

<?php
namespace Wordpress {

  function wp_is_writable( $path ) {
    if ( 'WIN' === strtoupper( substr( PHP_OS, 0, 3 ) ) )
        return win_is_writable( $path );
    else
        return @is_writable( $path );
  }

  function bool_from_yn( $yn ) {
    return ( strtolower( $yn ) == 'y' );
  }
}

// Global namespace
namespace {
  // Before/Antes PHP 7
  // use function Wordpress\wp_is_writable;
  // use function Wordpress\bool_from_yn;

  // PHP 7
  use function Wordpress\{wp_is_writable, bool_from_yn};

  if (wp_is_writable(__DIR__)) {
    echo __DIR__, ' is writeable', PHP_EOL;
  }

  echo bool_from_yn('y'), PHP_EOL;
}

use-namespaces.php

<?php
// Before/Antes PHP 7
// use Symfony\Component\Form\Extension\Core\Type\TextType;
// use Symfony\Component\Form\Extension\Core\Type\DateType;
// use Symfony\Component\Form\Extension\Core\Type\SubmitType;

// PHP 7
use Symfony\Component\Form\Extension\Core\Type\{TextType,DateType,SubmitType};

utf8-scapecode.php

<?php
$is_cli = false !== strpos(PHP_SAPI, 'cli');
$nl = $is_cli ? PHP_EOL : nl2br(PHP_EOL);

if ($is_cli) {
    echo "\u{2665}", $nl;
    echo "\u{267B}", $nl;
    echo "\u{260E}", $nl;
} else {
    $style = '<a href="." style="font-size: 32px; color: %s; text-decoration: none;">%s</span>' . $nl;
    echo sprintf($style, 'green', "\u{2665}");
    echo sprintf($style, 'red', "\u{267B}");
    echo sprintf($style, 'blue', "\u{260E}");
    echo '<button type="button">', "\u{267B}", '</button>';
}

/**
 * Print
 *
 * ♥
 * ♻
 * ☎
 *
 */