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Named elements of a table
Posted: Mon Jul 31, 2017 10:42 am
by peceha
That is something I just encountered and it made me wonder.
In the manual you can read:
You can access named elements of a table also in two ways:
b = a["name"]
b = a.name
Up to now, at the beginning of my script I had following table declaration:
Code: Select all
mapSettings = {
["minRmW"] = 3,
["minRmH"] = 3,
["maxRms"] = 5,
["rmChnc"] = 80,
["sparse"] = 50,
["loops"] = 50,
["rndDirTreshold"] = 80
}
and I decided to replace it with this:
Code: Select all
mapSettings = {
minRmW = 3,
minRmH = 3,
maxRms = 5,
rmChnc = 80,
sparse = 50,
loops = 50,
rndDirTreshold = 80
}
And now I had a lot of errors: "table field was not initialized" and it turned out that my old syntax was causing it:
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aLoc=bspSplit(0,0,#W,#H,mapSettings["maxRms"])
or from another table:
Code: Select all
colorReq.shadowOnOff=color["shadowOnOff"]
so I changed these entries to:
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mapSettings.maxRms
color.shadowOnOff
and it is working.
Have I misunderstood something here?
Re: Named elements of a table
Posted: Mon Jul 31, 2017 12:56 pm
by SamuraiCrow
The quotes around the variable name mean that the name of the element is literally what's between the quotes, not the contents of the variable with that name.
Re: Named elements of a table
Posted: Mon Jul 31, 2017 5:48 pm
by peceha
Yes , I'm aware of this.
What I don,t understand is why my program gave me plenty errors about table fields not being initialized - all I did was a change from (example):
t["field"]=0
to
t.field=0
then everytime there was something like function(t["field"]) in my script , I had an error message, so had to change it to function(t.field)
t.field is the same as t["field"], right? - i just checked it and it seems to be right.
Re: Named elements of a table
Posted: Mon Jul 31, 2017 5:58 pm
by Allanon
Hi peceah,
looking to one of your example :
Code: Select all
mapSettings = {
["minRmW"] = 3,
["minRmH"] = 3,
["maxRms"] = 5,
["rmChnc"] = 80,
["sparse"] = 50,
["loops"] = 50,
["rndDirTreshold"] = 80
}
This is not the same of:
Code: Select all
mapSettings = {
minRmW = 3,
minRmH = 3,
maxRms = 5,
rmChnc = 80,
sparse = 50,
loops = 50,
rndDirTreshold = 80
}
because there is no case distinction in table indexes, so for example:
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; SMALLER EXAMPLE
test = {}
test.Field1 = "Hello" ; <- The real index stored is all in lowercase!
DebugPrint(test.Field1) ; This will work
DebugPrint(test["field1"]) ; This will work
DebugPrint(test["Field1"]) ; This will trow an error
If you want to maintain case distinction you have to store and retrieve items using ["..."] :
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test = {}
test["Field1"] = "Hello"
DebugPrint(test["Field1"]) ; This will work
DebugPrint(test.Field1) ; This will trow an error
DebugPrint(test["field1"]) ; This will trow an error
I hope this helps
Re: Named elements of a table
Posted: Mon Jul 31, 2017 6:02 pm
by peceha
WOW
Thank You - that helped for sure !!!
Re: Named elements of a table
Posted: Mon Jul 31, 2017 6:42 pm
by Allanon
Great!
