PHP 5.4 : The elvis operator ?:

// Avant
$basket = $items ? $items : [];

// Avec Elvis
$basket = $items ?: [];

Spaceship operator

<=>

// Pre Spacefaring^W PHP 7
function order_func($a, $b) {
    return ($a < $b) ? -1 : (($a > $b) ? 1 : 0);
}

// Post PHP 7
function order_func($a, $b) {
    return $a <=> $b;
}

// Integers
echo 1 <=> 1; // 0
echo 1 <=> 2; // -1
echo 2 <=> 1; // 1

Typage faible : PHPWTF

// Wheeeee

var_dump(1 * '2' + true); //int(3)

var_dump(array(
    0 => 0, 
    '0' => '0', //écrase la valeur précédente
    0.0 => 0.0,  //écrase la valeur précédente
    false => false,  //écrase la valeur précédente   
));
/*
array (size=1)
  0 => boolean false
*/

var_dump((bool) (array) false); //bool(true)

in_array('abc', array(0)); //boolean true

PHP5 : type-hinting

function listenFormation($theodoer)
{
    if (!$theodoer->isHungry()) {
        return true;
    }

    return false;
}

listenFormation('kenny');
// PHP Fatal error:  Call to a member function isHungry() on string

function listenFormation(Theodoer $theodoer)
{
    if (!$theodoer->isHungry()) {
        return true;
    }

    return false;
}

listenFormation('kenny');
// PHP Catchable fatal error:  Argument 1 passed to listenFormation() 
// must be an instance of Theodoer, string given
// FAIL FAST

PHP7 : scalar type-hinting

function sendHttpStatus(int $statusCode, string $message) {
     header('HTTP/1.0 ' .$statusCode. ' ' .$message);
}

sendHttpStatus(404, "File Not Found"); // integer and string passed
sendHttpStatus("coucou", "tu veux voir mon status ?");
// Catchable fatal error: Argument 1 passed to sendHttpStatus() must be of the type integer, 
// string given

// So what ?
sendHttpStatus("403", "OK"); // string "403" coerced to int(403)

strict mode

<?php
declare(strict_types=1); // must be the first line

sendHttpStatus(404, "File Not Found"); // integer and string passed
sendHttpStatus("403", "OK"); 

// Catchable fatal error: Argument 1 passed to sendHttpStatus() must be of the type integer, 
// string given

return type declaration

<?php

function get404StatusCode(): int 
{
    return 404;
}

echo get404StatusCode(); // 404

function get404StatusCode(): int 
{
    return "quatrecentquatre";
}

echo get404StatusCode(); // Uncaught TypeError: Return value of get404StatusCode() 
// must be of the type integer, string returned

Exceptions

<?php

function isTheodoerStillAwake()
{
   throw new \Exception();
}

try {
    isTheodoerStillAwake();
} catch (\Exception $e) {
}

// Tout va bien

function wakeTheodoer($theodoer)
{
    $theodoer->wake();
}

try {
    wakeTheodoer('kenny');
} catch (\Exception $e) {
}

// Fatal error: Uncaught exception 'BadMethodCallException' with message 
// 'Call to a member function wake() on a non-object

Exceptions

<?php

function wakeTheodoer($theodoer)
{
    $theodoer->wake();
}

try {
    wakeTheodoer('kenny');
} catch (\Throwable $e) {
}

// Ouf