Android Question Array of array (and its initialization)

[StefanoAccorsi]

Hi there,
I searched in Google and here in the forum but can't find any example or tutorial on declaring an array of array and on how to initialize it.

I mean something like

((Int, Int), (Int, Int), (Int, Int), ...)

I started from the idea of an array of custom type:

Type Coord(x as int, y as int)
Dim arr() as Coord

This could be ok, but I need to manually initialize it with something like (in pseudo-Java code):

arr = Array of Coord(new Coord(1,4), new Coord(5,6), ...)

Is it possible to write something like this in B4A?

Otherwise, an array of array of two int could be ok, but I don't know how to initialize it, and even how to correctly declare it. Possibly something like:

Dim arr(Array(2) as Int) as ???

I wrote the code up there since it didn't give me syntax error!

And then, how to initialize it with something like:

arr = Array as ???((1,4),(5,6),...)

Thank you!

 

[LucaMs]

Use a Map.

Dim mapCoord As Map : mapCoord.Initialize
Dim Coord1(1, 4) As Int
Dim Coord2(5, 6) As Int
'...
mapCoord.Put(1, Coord1)
mapCoord.Put(2, Coord2)

 

[Erel]

You can create a multi-dimension array:

Dim a(10, 20) As Int
Dim b(10, 20, 30, 40) As Double)

However you cannot use the Array keyword with these arrays.

If you want to create an array of arrays then you should use a list instead.
A list can hold any type of objects including arrays.

Dim l1 As List
l1 = Array(Array As Int(1, 2), Array As Int (3, 4))
For Each a() As Int In l1
   Log(a(0) & ", " & a(1))
Next

Don't overuse arrays. It will be easier to work with lists, maps and custom types.

 

[LucaMs]

I'm envious for that Like from @ArminKH.
My solution is very similar to the Erel's one (also, it has the advantages of Maps).

 

[Erel]

You would have received a "like" if you made your code more elegant

Dim MapCoord As Map = CreateMap (1: Array As Int(1, 4), 2: Array As Int(5, 6))

 

[LucaMs]

You would have received a "like" if you made your code more elegant

Dim MapCoord As Map = CreateMap (1: Array As Int(1, 4), 2: Array As Int(5, 6))

To do it, I should have more than 2 bytes of brain memory: that "new" way to initialize a map did not remain in memory


Thank you, Erel

 

[LucaMs]

https://www.b4x.com/android/forum/threads/addtomap.43937/#post-267332

 

[StefanoAccorsi]

You would have received a "like" if you made your code more elegant

Dim MapCoord As Map = CreateMap (1: Array As Int(1, 4), 2: Array As Int(5, 6))

Damn, @Erel is frightful!!

Thank you guys.