Ar Construct

A function added by the Oblivion Script Extender.

Syntax:

(array_var) ar_Construct arrayType:string

Creates a new array_var and assigns it to an array variable. Must be called within the context of an OBSE expression such as Let. The parameter specifies the type of array to create: Array, Map, or StringMap.

• Array:

An Array behaves like arrays in most programming languages: the key is an unsigned integer starting at zero, and there are no gaps between elements. (In other words, if an element exists at indexes 1 and 3 then an element necessarily exists at 0 and 2). Attempting to access an element using a key which is greater than the highest key in the array results in an error. The only exception to this rule is during assignment: it is okay to assign a value to the key which is one greater than the highest key in the array.

• Map:

A Map associates numeric keys with values. Unlike an Array, a Map allows negative and floating point numbers to be used as keys and allows gaps to exist between elements.

• StringMap:

Like a Map, except the keys are strings. Keys are case-insensitive, so array[INDEX] and array[index] both refer to the same value. There is no practical limit on the length of the strings used as keys. StringMaps can be used to simulate C-style structs by associating named properties with data values.

Notes

• An array_var must be initialized before it can be used in expressions, either by explicitly initializing it using ar_Construct, assigning the value of another array_var to it, or assigning it the return value of a command returning an array such as GetItems.

• Most array operations should be performed within OBSE expressions such as Let or Eval statements.
• Array elements cannot be passed directly to most commands as arguments. *Assigning one array to another as in Let array_1 := array_2 causes both array_1 and array_2 to refer to the same array, as illustrated below:

 array_var a
 array_var b
 let a := ar_Construct Array
 let a[0] := "First elem"
 let b := a                  ; b now refers to the same array as a
 let b[1] := "Second elem"   ; array now contains two elements