Beginner PHP Tutorial - 45 - More on Expression Matching Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

and this is we're basically using
pattern matching to ensure that it
adheres to a certain standard so we can
use PR rag match for the P rag match for
this is a very very very powerful
function like I said I'm not going to go
through how we're going to check the
patterns if you go over to the php.net
manual you'll find plenty of information
on how to match specific things whether
it be URL so we could take out a
hostname from a URL but basically we're
basically looking for patterns within
strings and doing things with that and
there's a variety of ways you can do
this returned as an array etc etc so
what just for now that's basically the P
red-red P reg match function let's go
ahead and make this a bit more
interesting we're going to feed in a
string to a function and check if it's
got spaces so let's go ahead and create
our function and if you haven't already
looked at functions don't worry follow
it along the example anyway and if you
want to go back and look at functions
and how they work feel free to do so and
come back to the tutorial if you don't
understand what's going on so I'm going
to create a function called has space
and what we're going to do is we're
going to return true if this if the
specific string has a space and we're
going to return false if it doesn't so
we're going to feed in the string as an
argument up here so now what we're going
to do is we're going to say if and we're
going to use the pewag match function
again to see if we have likely defined
before a space inside a specific string
now the string comes from the argument
that we've just fed in so if this does
match then we can return a value of true
so we can return true here
otherwise we can return false okay so
now what we want to do is we want to
call this function down here but we want
to cool it inside an if statement
because we've got our function but as
far as it goes at the moment when we
refresh we don't have anything we
haven't called it so let's create an if
statement and say if has space and let's
feed in some text so this doesn't have a
space if this has space echo has a space
else
has no spaces
okay so ore has at least one space now
let's take this string out because I've
just thought we it would better defined
inside variable here and then we can
just feed this variable in through there
so let's recap of what we've done we've
created a string here
cool this doesn't have a space or with a
value this doesn't have a space with
absolutely no spaces in it and then
we're calling our function here and
feeding in this argument which is
essentially equal to this string here
and that's been processed here we're
checking on the pre mag a PRP reg match
which we've already looked at in the
last part in the first part of the
tutorial and then if this function
returns true which it will if it does
have a space then we're going to say a
have at least one space or has at least
one space otherwise we're going to
return false and we're going to say it
has no spaces so let's double check and
see if this works okay so it says now
has no spaces because this string
doesn't in fact have any spaces let's
just create one space in it and see what
happens okay so it now says has at least
one space now if we just create all the
spaces in it we need let's just put a
single quotation mark there and remember
to escape single quotation marks when
you're using single quotation marks
outside of your string data let's
refresh and it still says has at least
one space so that's a brief overview if
you like of the P reg match function and
we've created our own little application
here to check if a string data has a
space or not and but do feel free to go
and look up the P welcome P reg match
pattern checking and it's very very very
in-depth but once you do get your head
around it you'll be able to look it and
realize actually how useful it is for
checking patterns within strings