Pointers – Go Lang Practical Programming Tutorial p.4

what is going on everybody welcome to
part 4 of the go tutorial series in this
part what we’re really talking about is
pointers which is pretty much the last
element that’s going to be necessary for
you to understand the basic kind of go
web server example so also if you’re
like coming from something like Python
this is totally foreign to you so so
it’s probably a good idea we cover it so
the first thing I’m gonna go ahead and
do is kind of clean up what we’ve got
going on here so first of all we’re just
gonna be using format so I’ll get rid of
the parentheses there we’ll clean up
these two functions and I’ll just empty
out main because we don’t need anything
there
alright so let’s say we have a variable
and we’re gonna say it’s X colon equals
and we’ll say that if X is equal to 15
what type is 15 you should know now now
what we can say is a colon equals and
that’s going to point to X so the way
that we point to something is with the
ampersand and then the variable we want
to point to so this is gonna wind up
being the memory address I’ll just write
that out and then now let’s go ahead and
format dot print line a just so we can
see what we’re doing so let me bring up
a command line and go run go go boom so
that’s actual memory address where the
value for X’s is being stored so now
what we can do is like what if we so so
basically you if you want to point to
something use the ampersand but if you
want to read through a memory address
you use the asterisk or star so so what
we could say is format dot print line
asterisk a save that run that and you
see in this case you get 15 because
that’s that’s currently what the value
of x is now what if we said asterisk a
equals 5 what what do you think we’ll
wind up happening there so let’s go
ahead and save that run that whoops we
didn’t
anything else let’s go ahead and print X
now so format dot for its line X so now
X is actually equal to five because it’s
changed so so now like just just for fun
a the reading through of that memory
address of X so the reading through of
whatever’s at a equals whatever’s
through at a times every through day
that looks fun so what’s gonna be the
output there right you should be able to
visually look at this and know what’s
what’s gonna say but oh we still need to
print it out huh
let’s print let’s do format dot print
line X what happened hey there we go
we’re Matt dot print line X and then
also let’s let’s print out asterisk a
and that’s probably so we’ll save that
we’ll run that and as you can you
probably could have guessed it was going
to be five times five
but anyways pretty cool it’s it’s super
simple once you get used to it but it as
a foreign concept it gets kind of
challenging just know that anytime
you’ve got ampersand that’s the memory
address that’s leading to whatever
variable you pass and then if you want
to read what’s at that variable or
what’s at that memory address rather
you’re gonna use the asterisk alright so
that’s all for pointers and in the next
tutorial we’ll actually start with our
super basic web server example if you
have questions comments concerns
whatever you can feel free to leave them
below otherwise I will see you in the
next tutorial