I've seen lots of people say ":" is bad to use in coding, and you should use "." instead. Well my question is, how can I define the variable more clearly, so I can actually use "."
- EXAMPLE -
if(istype(M,/mob/Player)) M:Coolness ++
If I try to use a "." there, I would get Undefined Variable M:Coolness"
I've seen lots of people say ":" is bad to use in coding, and you should use "." instead. Well my question is, how can I define the variable more clearly, so I can actually use "."
- EXAMPLE -
> if(istype(M,/mob/Player)) > M:Coolness ++ >
If I try to use a "." there, I would get Undefined Variable M:Coolness"
if(istype(M,/mob/Player)) var/mob/Player/P = M P.Coolness++
The reason that the : operator can so often be bad is because it's basically telling the compiler not to check it. In other words, something like this would compile with the : operator:
obj/var/obj_variable = "This variable belongs to /obj."
//mob/verb/test() will give a runtime error, but will compile mob/verb/test() src << src:obj_variable
The above would compile, but it would give a runtime error since it can't read a non-existant variable. The . operator, on the other hand, would catch the mistake before it turns into a runtime error.
What Jon said is correct:
if(istype(M,/mob/Player)) var/mob/Player/P = M P.Coolness++
> obj/var/obj_variable = "This variable belongs to /obj." > > //mob/verb/test() will give a runtime error, but will compile > mob/verb/test() > src << src:obj_variable >
The above would compile, but it would give a runtime error since it can't read a non-existant variable.
Heh you should test this out yourself :). It will not compile. When using the colon operator it will check to see if the variable is within the datum you defined the variable as or one of its children. Should none of them have it it won't compile.
Thanks for answering my questions, and it helped my learn new BYOND coding things, but my last question is here, with this code I can use a ":" and it works, but using a "." doesnt...
mob proc Shop() var/Buyable = input("What unit would you like?")in list("Soldier","Mage") switch(Buyable) if("Soldier") var/Soldier = new/mob/Units/Soldier(null) src = /mob/Player src.Unit_List.Add(Soldier)
What you're doing there is manually setting the value of src, which isn't a good idea here. Furthermore, you're setting it to a type path; an uninitialized object.
You're also abusing usr (by default, input() boxes are sent to usr). Read the usr lecture.
Anyway, the following would work:
mob proc Shop() if(!istype(src,/mob/Player)) return switch(input(src,"What unit would you like?")in list("Soldier","Mage")) if("Soldier") var/mob/Units/Soldier/S = new() var/mob/Player/P = src P.Unit_List.Add(Soldier)
I want you to note a few things:
var/mob/Units/Soldier/S = new()
Notice the way I'm giving as much information to the compiler as possible about the soldier. That's a good rule of thumb: give the compiler as much information as you can when defining variables.
var/mob/Player/P = src
I want you to realize here that since DM is a loose-typed language, while this tells the compiler to think of P as a /mob/Player, it doesn't actually guarantee it! We guaranteed that earlier in the proc:
if(!istype(src,/mob/Player)) return
Now, while I hoped you've learned more about type casting from the above, I want you to release a much easier way to do this: define your proc under /mob/Player in the first place!
mob/Player/proc/Shop() switch(input(src,"What unit would you like?")in list("Soldier","Mage")) if("Soldier") src.Unit_List.Add(new/mob/Units/Soldier)
Since Shop() now belongs to /mob/Player, src is guaranteed to be a /mob/Player!
Heh you should test this out yourself :). It will not compile. When using the colon operator it will check to see if the variable is within the datum you defined the variable as or one of its children. Should none of them have it it won't compile.
Doh! Forgot about that!
Here's a better example of colon failure:
obj/var/obj_variable = "This variable belongs to /obj."
//atom/proc/test() will give a runtime error if the atom is not an obj, but will compile atom/proc/test() world << src:obj_variable
/mob/player is an object type, not an actual object. You need something like in the example given you previously in this thread.
var/mob/player/M=src src.Unit_List.Add(Soldier)
However, the way you did that makes it appear as though the src will always be of type /mob/player. If that is so, you can define the proc to be owned by that type instead.
