Overview of PHP shorthand

One of my favorite "tricks" in PHP is to use the array union operator when dealing with situations such as functions that take an array of arguments, falling back on default values.

For example, consider the following function that accepts an array as an argument, and needs to know that the keys 'color', 'shape', and 'size' are set. But maybe the user doesn't always know what these will be, so you want to provide them with some defaults.

On a first attempt, one might try something like this:

function get_thing(array $thing)
{
    if (!isset($thing['color'])) {
        $thing['color'] = 'red';
    }
    if (!isset($thing['shape'])) {
        $thing['shape'] = 'circle';
    }
    if (!isset($thing['size'])) {
        $thing['size'] = 'big';
    }
    echo "Here you go, one {$thing['size']} {$thing['color']} {$thing['shape']}";
}

However, using the array union operator can be a good "shorthand" to make this cleaner. Consider the following function. It has the exact same behavior as the first, but is more clear:

function get_thing_2(array $thing)
{
    $defaults = array(
        'color' => 'red',
        'shape' => 'circle',
        'size'  => 'big',
    );
    $thing += $defaults;
    echo "Here you go, one {$thing['size']} {$thing['color']} {$thing['shape']}";
}    

Another fun thing is anonymous functions, (and closures, introduced in PHP 5.3). For example, to multiple every element of an array by two, you could just do the following:

array_walk($array, function($v) { return $v * 2; });

Nobody mentioned ??!

// Example usage for: Null Coalesce Operator
$action = $_POST['action'] ?? 'default';

// The above is identical to this if/else statement
if (isset($_POST['action'])) {
    $action = $_POST['action'];
} else {
    $action = 'default';
}

Here are some of the shorthand operators used in PHP.

//If $y > 10, $x will say 'foo', else it'll say 'bar'
$x = ($y > 10) ? 'foo' : 'bar';

//Short way of saying <? print $foo;?>, useful in HTML templates
<?=$foo?>

//Shorthand way of doing the for loop, useful in html templates
for ($x=1; $x < 100; $x++):
   //Do something
end for;

//Shorthand way of the foreach loop
foreach ($array as $key=>$value):
   //Do something;
endforeach;

//Another way of If/else:
if ($x > 10):
    doX();
    doY();
    doZ();
else:
    doA();
    doB();
endif;

//You can also do an if statement without any brackets or colons if you only need to
//execute one statement after your if:

if ($x = 100)
   doX();
$x = 1000;

// PHP 5.4 introduced an array shorthand

$a = [1, 2, 3, 4];
$b = ['one' => 1, 'two' => 2, 'three' => 3, 'four' => 4];

PHP 5.3 introduced:

$foo = $bar ?: $baz;

which assigns the value of $bar to $foo if $bar evaluates to true (else $baz).

You can also nest the ternary operator (with proper use of parenthesis).

Other than that, there is not much else about it. You might want to read the documentation.