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<h1>Working with variables</h1>
<p>
Variables in PHP are non-typed. A variable can thus hold any possible type:
an integer, string, a floating point number, and even an object or an array.
C++ on the other hand is a typed language. In C++ an integer variable always
has a numeric value, and a string variable always hold a string value.
</p>
<p>
When you mix native code and PHP code, you will need to convert the non-typed
PHP variables into native variables, and the other way round: convert native
variables back into non-typed PHP variables. The PHP-CPP library offers the
Php::Value class that makes this a very simple task.
</p>
<h2>Zval's</h2>
<p>
If you have ever spent time on writing PHP extensions in plain C, or if you've
ever read something about the internals of PHP, you must have heard about zval's.
A zval is a C structure in which PHP variables are stored. Internally, this zval
keeps a refcount, a union with the possible types and a number of other members
too. Every time that you access such a zval, make a copy of it, or write to
it, you must break your head to correctly update the refcount, and/or split the
zval into different zvals, explicitly call copy constructors, allocate or
free memory (using special memory allocation routines), or choose not to
do this and leave the zval alone.
</p>
<p>
This all is crazy difficult and a big source for mistakes and all sorts of bugs.
</p>
<p>
And to make things even worse, there are literally hundreds of different
undocumented macro's and functions in the Zend engine that can manipulate these
zval variables. There are special macro's that work on zval's, macro's for
pointers-to-zval's, macro's for pointer-to-pointer-to-zval's and even macro's
that deal with pointer-to-pointer-to-pointer-to-zval's.
</p>
<p>
Every single PHP module, every PHP extension, and every builtin PHP function
is busy manipulating these zval structures. It is a big surprise that nobody
ever took the time to wrap such a zval into a simple C++ class that does all
this administration for you. C++ is such a nice language with constructors,
destructors, casting operators and operator overloading that can encapsulate all
this complicated zval handling.
</p>
<p>
And that is exactly what we did with PHP-CPP. We have introduced the Php::Value
object with a very simple interface, and the takes away all the problems of zval
handling. Internally, the Php::Value object is a wrapper around a zval variable,
and the completely hides the complexity of zval handling.
</p>
<p>
So, everything that you always wanted to ask about the internals of PHP, but
were afraid to ask: just forget about it. Sit back and relax, and take a look
how simple life is if you use PHP-CPP.
</p>
<h2>Scalar variables</h2>
<p>
The Php::Value object can be used to store scalar variables. Integers
</p>
<h2>Arrays</h2>
<p>
This section is not finished yet
</p>
<h2>Objects</h2>
<p>
This section is not finished yet
</p>
<h2>Functions</h2>
<p>
This section is not finished yet
</p>
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