Hidden Features of PHP? [closed]

Answer 1

One nice feature of PHP is the CLI. It's not so "promoted" in the documentation but if you need routine scripts / console apps, using cron + php cli is really fast to develop!

Answer 2

Documentation. The documentation gets my vote. I haven't encountered a more thorough online documentation for a programming language - everything else I have to piece together from various websites and man pages.

Answer 3

Then "and print" trick

<?php $flag and print "Blah" ?>

Will echo Blah if $flag is true. DOES NOT WORK WITH ECHO.

This is very handy in template and replace the ? : that are not really easy to read.

Answer 4

Arrays. Judging from the answers to this question I don't think people fully appreciate just how easy and useful Arrays in PHP are. PHP Arrays act as lists, maps, stacks and generic data structures all at the same time. Arrays are implemented in the language core and are used all over the place which results in good CPU cache locality. Perl and Python both use separate language constructs for lists and maps resulting in more copying and potentially confusing transformations.

Answer 5

I'm a little surprised no-one has mentioned it yet, but one of my favourite tricks with arrays is using the plus operator. It is a little bit like array_merge() but a little simpler. I've found it's usually what I want. In effect, it takes all the entries in the RHS and makes them appear in a copy of the LHS, overwriting as necessary (i.e. it's non-commutative). Very useful for starting with a "default" array and adding some real values all in one hit, whilst leaving default values in place for values not provided.

Code sample requested:

// Set the normal defaults.
$control_defaults = array( 'type' => 'text', 'size' => 30 );

// ... many lines later ...

$control_5 = $control_defaults + array( 'name' => 'surname', 'size' => 40 );
// This is the same as:
// $control_5 = array( 'type' => 'text', 'name' => 'surname', 'size' => 40 );

Answer 6

__autoload() (class-) files aided by set_include_path().

In PHP5 it is now unnecessary to specify long lists of "include_once" statements when doing decent OOP.

Just define a small set of directory in which class-library files are sanely structured, and set the auto include path:

set_include_path(get_include_path() . PATH_SEPARATOR . '../libs/');`

Now the __autoload() routine:

function __autoload($classname) {
    // every class is stored in a file "libs/classname.class.php"

    // note: temporary alter error_reporting to prevent WARNINGS
    // Do not suppress errors with a @ - syntax errors will fail silently!

    include_once($classname . '.class.php');
}

Now PHP will automagically include the needed files on-demand, conserving parsing time and memory.