Ruby Programming Tutorial - 31 - Hashes Video Lecture | Introduction to Coding with Ruby - Back-End Programming

what's going on guys welcome to another
tutorial on Ruby and in this lesson I
want to talk to you guys about something
called hashes now hashes are kind of
like arrays but not exactly they have
something called keys and values and
instead of like a list of items like an
array it's more like a dictionary and
I'll show you how let me go ahead and
give you an example I'm going to name
mine hat my hash example and like I said
you set it equal to a list but not just
a list of item a list of keys and values
now you can think of these as like terms
and definitions so the first thing you
do is you give it the key or key word so
Bucky and after that you use this little
equals this little contraption here that
looks like an arrow
it's the equals greater than sign and
now after the key you give it the value
so what is this key word equal to or
what is pretty much the definition of
this word Bucky
coolest guy ever so there we have one
term or key let's go ahead and do
another one say we were making a list of
people and their qualities so next let's
go ahead and put a person named Emma and
Emma is let's just say that she's a very
nice gal will say that's Emma Roberts
and now let's go ahead and I don't know
let's go ahead and get one more person
Peter and remember any time you want to
separate the key and value just go ahead
and put equals greater than and we'll
just say this is a family guy dude so
now we have a list of three people keys
and values go ahead and hit enter and
that's going to go ahead and store it in
your memory
now just like arrays we can call a
couple methods on this for example if we
go ahead and print example which was the
name of our hash then go ahead and get
the size of it
and it says three now which pretty much
means there are three things in this
list or three people Bucky Emma and
Peter sorry guys I'm getting over a cold
I was actually sick for like three weeks
I had no voice whatsoever so if I sound
a little funny or if I you know just
start coughing in the mic spewing out
blood that's probably why but anyways
aside from this we can also do things
like print out the values of these keys
so for example what we carried was
basically a dictionary with terms and
definitions people's names and
descriptions or descriptive words so if
we want to go ahead and get the
description or definition we just want
print the name of your hash which is
example and the key in little square
brackets so Bucky go ahead and hit enter
and it comes back coolest guy ever
so there you have if you want to make
like a dictionary in Ruby or something
this is probably your best bet but what
if you made this hash in your like
that's pretty cool but there's one
little thing that's wrong with this
program someone wrote Bucky is the
coolest guy ever when it was really
supposed to be the fattest guy ever oh
man how did we mess that up so this is
how you change a key and give it an
alternate value go ahead and type the
name of your key which is example Bucky
that means we're talking about the Bucky
one and just set it equal to new value
like fattest guy ever we're right ever
like that ghetto style now go ahead and
hit enter and it stores it and if we go
ahead and print out the hash print
example Bucky and now says fattest guy
ever so there's how you create a simple
hash again like I said it's kind of like
an array but an array is basically just
a list of stuff this is a more complex
list it's kind of like a dictionary
where you have terms and definitions and
they're technically called keys and
values if you were to take a test or
something so in order to change a key
later on you just go ahead and set it
equal to a different value so there you
go there's a really basic explanation of
what hashes I think you guys for
watching and I'll see you guys in the
next video