Beginner PHP Tutorial - 69 - Working with $_GET Variables Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

okay this is Alex from PHP academy'
creating this tutorial set for the new
Boston now we're up to the point in our
forms where we're looking from the
previous example about how do we create
a form and about the action and the
method like you can see here we're now
going to talk about how we use PHP to
pick up these variables now at the
moment we're processing three variables
through the get method and this is day
date and year and we can see this in our
browser by here now at the moment we're
processing these however we need a PHP
page to pick these variables up and we
want to do something with them we need
them to be processed and displayed back
to the user in this example so in PHP
now what we want to do is we want to
create first of all a few checks the
first check we need to do is does it
exist or in real terms
has it been submitted or submitted this
is the first thing we need to check for
the second thing we need to check for is
is it empty so or in actual terms does
the value equal null or does it equal
nothing so for now I'm going to put an R
cuz it's the same thing so the third
thing we need to do is display back to
user and in this whole process the third
process we need to grab it from the URL
so we need to grab this variable here
contents of this variable and the
contents of this variable and it's
easier than you might think so let's put
these in a comment just here just so we
can keep an eye on them okay so the
first thing we need to do is do this the
point one does it exist and to do this
we set up an if statement we create a
block and we say if is set and this is a
function so is set inside of it we need
to do dollar underscore and get this is
how we declare the get or this is how we
grab from the
get variable associative array day now
what this is doing is it's checking if
we've in fact submitted the form and
this here is there and which it is at
the moment I mean even if we submit it
without any data it still means it's set
it's set it doesn't equal anything but
it's still set so in fact maybe we'll
before we proceed with this itself we
can have a look at just echoing them out
normally so if I was to echo dollar
underscore get day let's type in a day
here Monday click submit and you can see
it's echoed Monday so it's it's taking
this value here using this structure and
it's just echoing it straight on to the
page above the form now this is
obviously really unsafe we could be we
could be dealing with protesting
anything really so we need to check this
if it's set first or if it's empty and
then we need to re declare some
variables and use the HTML entities
function to sort of get sort of process
and any HTML code that might be input
into them as text to be displayed but
we'll come to that later
so if is step day as long as that equals
true we can continue in this blog but we
also need to say and is set using
exactly the same format for this is set
date and is set dollar underscore get
yeah so as long as we've clicked the
submit button and all these form fields
have been submitted as a variable we're
okay okay otherwise we're not so
otherwise we're not going to display
anything so let's go back to the index
dot PHP as it is so day date and year we
click Submit okay that's that means it's
been submitted the form has been
submitted now inside of this we need to
make a few more checks so we need to say
if not
empty we're using another function here
which is the empty function dollar in
fact now what we can do before we do
that is we can read to clear these
variables so day equals dollar
underscore get day and then date equals
dollar underscore get date year equals
dollar underscore get ya now we can say
if is not empty day with the dollar sign
and not empty date and not empty year
and we can echo okay otherwise we want
to say fill in all fields so let's test
this back to our index page if I click
Submit fill in all field so fields fill
in all fields now if we do type in say
Monday and 31st but we forget to enter
the gear we're still checking for all of
them so it still says fill in all fields
so Monday 3-1 and 2011 click Submit and
it's okay so now what we can do is we
can display these out to the user
in this format so echo it is day space
date space here
and that's it so as long as let's go
back to our index dot PHP page as long
as we enter Monday 3 1 2011 or enter
anything in here and we click Submit
it will just be displayed like this