Ruby Programming Tutorial - 27 - Beginning Arrays Video Lecture | Introduction to Coding with Ruby - Back-End Programming

what is up my friends welcome to your
27th Ruby tutorial now in this lesson I
want to talk to you guys about something
called an array now arrays are basically
just lists of items so let me go ahead
and show you guys how to create one real
quick say you want to have a list of
numbers or something go ahead and write
the name just like a variable name I'm
gonna call this array Boston why not and
now in square brackets go ahead and type
in your list now in your array you can
have a bunch of different things like
numbers you can have like people's names
string arrays but I'm just gonna go
ahead and create a real simple list of
numbers 3 5 7 98 and 321 now go ahead
and hit enter and bam look at that your
array is created so basically what you
did was you created a list now this list
is technically called the Boston array
now let's go over a couple vocabulary
terms first because I don't want to
confuse you guys so I want to clear
things up you know these items in the
list which is 3 5 7 98 321 whenever
you're talking about erase the items in
the list are actually called the
elements so technically if you're taking
a test you would say that this array has
5 elements 3 5 7 98 and 321
now clearly like I said this array has
five elements and in order to access
each individual element the first thing
we need to do is find out their position
or index so just remember that whenever
you're talking about erase and don't
forget this for your test if you're in
college or high school or something
inside an array each of these things is
called an element and their position is
called their index so the last point I
want to take note of for this tutorial
is whenever you are working with erase
you don't start counting at position one
like people do computers always start
counting in zero so this one is it index
zero this one is index one two three
four so now let me go ahead and show you
guys how to access this in
order to access each individual element
just go ahead and write the name of the
array which is Boston and inside square
brackets write the index number so let's
go ahead and just write zero now hit
enter and check it out it prints out
three why does it print out three
because the zero of index is the first
index which is three so now let's go
ahead and do another one like I don't
know three and check it out can you guys
guess what we're gonna get this is zero
one two three so we should get 98 BAM 98
right there so that is basically how to
access the individual elements in an
array basically just write the array
name in the index right after it and
this one goes from zero to four now you
can also do things other than printing
it out for example if you wanted to
change the value of one of the elements
check it out go ahead and write the name
just like you would whenever accessing a
variable now let's change the value of
this third one which is zero one two so
right now Boston two equals seven see
that but we want to change the value of
it so let's just go ahead and assign a
new value just like we were changing the
value of a variable so now instead of
seven let's give it a value of 66
so basically we're saying okay instead
of having a seven at location number two
we want to change that value to 66 now
go ahead and hit enter and it says 66
now you can either just print out the
array like this puts Boston and hit
enter and it's going to go ahead and
print out all your elements or you can
just go ahead and type the name of the
array an interactive Ruby now whenever
you hit enter
it gives it a kind of a neater format so
as you can see instead of having three
five seven 98 3 21 that second index is
now changed to its new value which is 66
so that is basically how you create an
array now remember the items in arrays
are called elements and instead of
positions they're called indexes and you
always start counting with the number 0
not 1 so there you go hopefully
guys understand a little bit more about
race if you don't watch the video again
but if you do you're ready to move on to
the next tutorial where we're gonna be
talking about the cool things that you
can do with the race so thank you guys
for watching don't forget to subscribe
and I'll see in the next video