Beginner PHP Tutorial - 40 - Multi-dimensional Arrays Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

this is Alex from PHP academy' dog with
another tutorial for the new Boston now
in this tutorial we're going to be
looking at multi-dimensional arrays now
multi-dimensional arrays put really
really put into use or into practice the
use of arrays now as it stands we've
created this array at the moment we have
an associative array with different food
types here and we've assigned values of
the amount of calories in each food so
we've given an example of how an
associative array can be useful now
we're going to move on to something
slightly more complicated which is
multi-dimensional arrays it sounds more
complicated than it is but in actual
fact the basic concept of this is an
array inside an array and this can be
multi-dimensional so it can be a two
dimensional array and three dimensional
array and so on and so forth
and you need to really think about this
as categories now in this example I'm
going to be creating two categories I'm
going to creating a category called
healthy and unhealthy and then inside
these different categories I'm going to
be adding different types of food so I'm
going to class pizzas oh sorry pizza as
unhealthy and I'm going to be classing
salad vegetables there vegetables
and pasta as healthy food so this is
basically a multi-dimensional array
because we're going to have an element
two elements healthy and unhealthy and
then we're going to have more arrays and
pizza is going to be within and around
itself and salad vegetable and pasta is
going to be in the right
in fact we'll add another another
unhealthy I'll say icecream okay so this
is what we want to achieve so let's
modify underneath here will comment this
out just so it's not going to be
taken as code okay so we've commented
that out this is essentially what we
want okay so this is the this is the top
array so let's delete everything we've
got inside the first thing we're going
to do is create two elements to our
array the first one is healthy the
second one is unhealthy okay so now what
we want to do is we're creating
essentially an associative array because
I want to add a value to this and a
value to this like we did in the
associative arrays tutorial but now
instead of assigning a value you may
think oh yeah I'm going to start to
assign salad as healthy and then blah
blah blah it's going to get all mixed up
so what we do is we take it into another
dimension and we say we're assigning the
value so we have created an array inside
an array so we're already talking into a
second dimension so if I add another
array in here let's just run this to
prove that is going to work ok yes we're
not receiving any errors at all now
inside these arrays we can start to add
our our foods so let's add salad
vegetables' pasta and then in unhealthy
let's add pizza and ice cream okay so
now we've essentially created a
multi-dimensional array what we can do
is we can bring this down to make here
sort of look a look a bit better so pull
this down to here it's a bit tricky with
this text editor that I'm using but you
get the general idea of how we can how
we can make it you know look a bit a bit
more easy to read if you like so let's
get rid of this here just so a bit
neater okay so let's run this and to
make sure everything's working
yep we've not received any errors so now
how are we going to access each element
of this array so what we've essentially
done is we've created an associative
array with the value of the of the
associative healthy and unhealthy as an
array so we've created a
multi-dimensional array so how are we
going to access these different elements
or we can echo out food again remember
we're using our square brackets and then
we address healthy but then what we do
is we need to access either element of
either room key 0 1 or 2 so what how do
we do this you know we need to add
something around here to two out be able
to access that all we do is we put
another pair of square brackets next to
it and then we type the element so as
this stands we're accessing the array
food the key of healthy here and then
inside that the first key which is salad
so we're essentially here echoing out
salad now you can already see how this
is to start starting to pull together
into a database type structure so let's
just refresh and see if that works
we're echoing salad now we can change
this to make so perhaps two that's going
to echo out pasta and let's refresh
pasta okay so we can obviously change
this to unhealthy and access element 1
which would be ice cream so you can see
how we can do this and change it and you
can see now how it's got multiple
dimensions to this array so that is
basically an and a multi-dimensional
array in PHP and how we declare it and
also how we access each each element