For the last few months I had quite a few MySQL blog posts and didn't have anything from my "new features in PHP [trunk|5.4]" series. This article is a bridge between those two. The PHP 5.4 NEWS file has a small entry:

MySQLi: Added iterator support in MySQLi. mysqli_result implements Traversable. (Andrey, Johannes)

From the outside it is a really small change and easy to miss. The mentioned class, mysqli_result, implements an interface which adds no new methods. What once can't see is that this relates to some internal C-level functions which can be called by the engine for doing a foreach iteration on objects of this class. So with PHP 5.4 you don't have to use an "ugly" while construct anymore to fetch rows from a mysqli result …

I was writing about PHP.next before, many things improved there meanwhile. Most notably we have a committed version number: The next PHP release will be called PHP 5.4. The topic I want to talk about today is "Improved application portability" which covers multiple small changes which aim at making it simpler for developers to write applications working on any PHP setup.

Separating <?= from short_open_tags

PHP knows quite a few ways to separate PHP code from surrounding text (usually HTML), most applications use <?php as that works on every system. There is a short form of this, <?, which can be disabled using php.ini's short_open_tags setting. Being able to disable this is important when embedding PHP code into XML documents containing XML processing instructions. Now we also have …

So in my blog series I try to cover all additions to PHP trunk so I have to mention scalar type hints.

<?php
function print_float(float $f) {
    echo $f."\n";
}

for ($i = 1; $i < 5; $i++) {
    print_float( $i / 3 );
}
?>
        

0.33333333333333
0.66666666666667

Catchable fatal error: Argument 1 passed to print_float() must be of the type double, integer given, called in typehints.php on line 7 and defined in typehints.php on line 2

Is expected behavior in PHP's trunk. If you want such a thing to work please use the numeric type hint.

In case that wasn't enought fun: There's more!

<?php
function handle_result(int $i) {
    echo $i."\n";
}

$pdo = new PDO("mysql:host=localhost;dbname=test", "user", "pass"); …