A showcase of some new features in PHP 7.1. Can read about it at antonydandrea.com/new-features-in-php-71. The file itself probably won't run, you can just copy and paste these functions individually to experiment.

php71Features.php

<?php
/**
 * Demo of Nullable Types. The ?string states that
 * the function can return a string or Null.
 */
function getItem($id) : ?string
{
    $animals = array("cat", "dog", "hamster", "rabbit");
    if (isset($animals[$id])) {
         return $animals[$id];
    } else {
        return null;
    }
}
var_dump(getItem(5));

/**	
 * Indicating the nullable type being used as a parameter.
 */
function getNumberOfChars(?string $string) 
 {
	   $numberOfChars = 0;
	   if (!is_null($string)) {
			$numberOfChars = strlen($string);
	   }
	   return $numberofChars;
 }


/**
 * Demo of the void type.
 */
function doSomethingRandom() : void
{
    rand(0,10) * rand(0,10);
}
doSomethingRandom();

/**
 * Pre 7.1 use off the list function.
 */
$animals = array("cat", "dog", "hamster", "rabbit");
list($animal1, $animal2, $animal3, $animal4) = $animals;

print $animal1;
print $animal2;
print $animal3;
print $animal4;

/**
 * From 7.1 you can use keys and so deconstruct associative arrays.
 */
$animals = array("feline" => "cat", "canine" => "dog", "cricetine" => "hamster", "leporine" => "rabbit");
list("cricetine" => $animal1, "feline" => $animal2, "leporine" => $animal3, "canine" => $animal4) = $animals;

print $animal1;
print $animal2;
print $animal3;
print $animal4;

/**
 * Numeric keys can also be used so you could deconstruct in any order.
 */
$animals = array("cat", "dog", "hamster", "rabbit");
list(2 => $animal1, 0 => $animal2, 3 => $animal3, 1 => $animal4) = $animals;

/**
 * From 7.1, you can use this shorthand usage of list() with just [].
 */
$animals = array("cat", "dog", "hamster", "rabbit");
[2 => $animal1, 0 => $animal2, 3 => $animal3, 1 => $animal4] = $animals;
print $animal1."\n";
print $animal2."\n";
print $animal3."\n";
print $animal4."\n";

/**
 * Demo of catching multiple Exceptions.
 */
class CustomException extends Exception{}

class AnotherException extends Exception{}

/**	
 * Throws one of the two exceptions declared above.
 */
function throwException()
{
    $i = rand(0,1);
    if ($i === 0) {
        throw new CustomException;
    } else {
        throw new AnotherException;
    }
}

/**
 * This is how you would have to do it < PHP 7.1, and still 
 * can if you wish.
 */
try {
    throwException();
} catch (CustomException $e) {
   print "there was an error\n";
} catch (AnotherException $e) {
    print "there was an error\n";
}

/**	
 * PHP 7.1 way of handling multiple exceptions.
 */
try {
    throwException();
} catch (CustomException | AnotherException $e) {
   print "there was an error\n";
}
*/

/**
 * Demonstrating the ability of changing the visibility of 
 * class constants. The var_dump would cause an error as the constant
 * is private.
 */
class MyClass
{
    private const SOME_CONSTANT = 10;
}

$class = new MyClass;
var_dump($class::SOME_CONSTANT);