So, now we're going to connect two of my favorite things about PHP.
We're going to connect the request response cycle and PHP arrays. So let's take a look.
Remember our happy little request response cycle that I love so much?
And that is you're sitting out here, you click on the link,
the browser sends a request with HTTP,
Apache, our web server, retrieves it.
It says, oh this is some PHP code,
so I'm going to start this thing up, start your code up.
And if on the end of your URL there are these parameters like?x=2,
actually these values and then &y=1,
these two values get parsed and put automatically into a global array,
that I've already mentioned called $_GET.
So this is a variable that is defined before the first line of your code executes.
And so, if you want to see what this value is,
you can say $_GET[‘x’].
So you don't have to write any of this parsing code,
PHP understands the request responsible,
request response cycle with these get parameters,
parses the get parameters and puts them into array $_GET,
and then you just write your code,
and then of course you send back HTML which goes back in parses in the DOM,
and then you get to see your next page.
Okay? So, we look at data that's coming from the browser often,
in the form of what are called super global arrays.
And so, here we can take at least a quick print.
This is a PHP file.
You can run it right here with x and y.
And so, it'll come in, remember that PHP files are HTML until we tell them otherwise.
We're going to run a pre tag just so we
don't get new lines because there's new lines here.
If you don't have pre tag, it's going to wrap it all up,
so it'll be one long line.
I sometimes don't put the pre tag out because I can read it,
but it's a lot easier to read if you do put a pre tag out.
So I'm going to print this $_GET.
So, this is the first line of code.
$_GET came from these two parameters.
So these two parameters are parsed and placed in the $_GET under x and y.
And that just saves you because it turns out it's not as simple as it looks.
If you are splitting and doing some other splitting,
it might convert these things because there's
actually weird characters that can go in here etc.
You know, that's not your problem, that's PHP's problem.
It parses all these things and puts them in an array, end of story.
I'm going to print it out with print_r() and we'll print it out again with var_dump,
just because var_dump is a little more explicit.
But basically, these things go into this array and you just access that array,
and those are the GET parameters.
Because this is an HTTP GET because I hit enter here, HTTP GET.
So it's the parameters after the question mark.
So this question mark,
the question mark here,
and then key value and then ampersand,
next key value, ampersand,
next key value etc.
So you can add these to the end of a URL,
and pass them right into the GET array and PHP does that.
It's called a super global
because it exists in the main code and in any function within all of PHP.
So, that sort of zooms us through the fun stuff that we can do with PHP arrays,
and so we'll see you in the next lecture.
