# Altirra BASIC - internals

## Variable formats

Type | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7
--- | --- | --- | --- | --- | --- | --- | --- | ---
Number | $00 | Var ID | Number
Array (undimensioned absolute) | $40 | Var ID | Address | Dim 1 | Dim 2
Array (dimensioned relative) | $41 | Var ID | Offset | Dim 1 | Dim 2
Array (dimensioned absolute) | $43 | Var ID | Address | Dim 1 | Dim 2
String (undimensioned absolute) | $80 | Var ID | Address | Length | Dimension
String (dimensioned relative) | $81 | Var ID | Offset | Length | Dimension
String (dimensioned absolute) | $83 | Var ID | Address | Length | Dimension