GameMaker: Studio - Understanding Errors Video Lecture | Game Maker Tutorial: Build Games from Scratch - Game Development

alright guys how's it going just a quick
video to talk about a problem that I
think a lot of people have when their
first time to work especially with like
code and stuff and game maker they'll do
like they'll put all the code together
for watching the tutorials or something
we'll run this and then boom I'll look
at some code error in that place and
because there's kind of a lot of text
and stuff going on in here they won't
necessarily know anything about that and
most people's first reactions are there
seems to be there just like copy and
paste this into like a message to me or
a comment or something and obviously I
forgot your floods of all this text and
stuff I don't have time to read it all
but like um a lot of the time it's the
same issue and the mo of the most common
code error you can get when you're
working with code is it is pretty much
this one and I'll come to explain it in
a second one of the things I don't
really like I suppose about a game make
a studio specifically as opposed to game
maker one of a few things I don't really
like is the done it's much harder to
read these code errors before it would
tell you something like it was very much
more straightforward with a terrorism
would just say like a unknown variable
add something or other line something
rhythm and while this does actually give
you more information about the errors
it's kind of hard to read but what's
going on here is if you see something
like this and you see this line here
variable get like this push execution
area there yeah sorry
push execution area push execution out
we'll get there in the end
push execution error variable get and
then like something dot and then a word
over here that all it means is it's
trying to find a variable that you've
mentioned somewhere in your code that it
can't find and that could be rude in a
million of different sort of problems
but it usually comes down to you having
spelled something wrong or not having
declared a variable elsewhere like it's
trying to see Oh add a to B but you've
never told it what a is and you know
that's basically what's going wrong so
whenever you get a quick like
Americans I've always just they have a
quick look for this line specifically
because I've seen in so many comments so
many messages push execution arrow
variable get and then that's how you
know that the problem is it can't find a
variable this minus one dot here like
that's just referring to the instance
inside the code that it like is trying
to reference it like if you were naming
like a global variable I think this will
be something like minus six minus one
just means like itself so it tells you
it's in the step of then it's action
number one of the stepper then for the
object object player so you know it
gives you all the information you really
need here and it says okay it's trying
to find the variable referring to itself
VK underscore left somehow or other I'm
fair enough and then it's here it says
tells you exactly what line of code it's
at as well so it says ant you know in
the object in the step it then on the
very first line of code if keyboard
check underscore direct VK underscore
left X minus equal to and now if you
know if you you know a little bit smart
you can probably work out already what
the problem is here it's trying to find
VK left and in here and this is the line
or the problem is that I mean let's just
go have a look at that line an object
from the scope layer in the step event
the first action and you can see the
problem here already because we've got
all these uh options that up here for
our own keyboard to move the character
around and there's the let set to the VK
VK down VK right for the different keys
but then this one is VK left and
obviously left isn't a direction we want
left you can see it's gone red there
this one we just have this and before it
thinks there's some sort of variable in
there so it's trying to say or was
d-calif I don't know what that is and
then it throws up an unknown variable
error that's all that's happening so
that's the typical kind of problem you
can run into with with that specific
error and it is very difficult to kind
of read those errors if you've never
seen them before but if you just kind of
you know you think about it and you
break it down like like I just did you
can go back and look at how I broke it
down you can tell it's actually telling
you a lot of information
about what wrong and that's how you
learn how to debug these kind of things
and so on so forth the variable errors
like that are usually just something
like a misspelled variable or like
you're referring to something like a
mystical potato for example that will
try when i press left to to subtract
potato from X but it won't know what
potato is so I mean if I run that just a
dentistry as well I press left moon
variable get minus one potato see it
doesn't know what that is and then it
tells you the same line of code that it
was at and you can see the problem then
you can just go in you can fix that or
you can just set potato to equal
sentinel point you get the idea anyway
that's just there to just hopefully
clear up a little bit about how you
solve those errors and hopefully leave
you with a little bit of a better
understanding of how the error reporting
system and game maker works all right
thanks for watching hope that was
helpful and wasn't too rambling and bad
and I'll catch you guys next time
thanks for watching guys