F# Array type is a data collection where elements are contiguous and has random access in constant time (see Wikipedia article about arrays).

> [|1 .. 10|];;
val it : int array = [|1; 2; 3; 4; 5; 6; 7; 8; 9; 10|]

> [|1 .. +2 .. 10|];;
val it : int array = [|1; 3; 5; 7; 9|]

> let arr = [|1 .. +4 .. 30|];;
val arr : int array

> arr.[2..5];;
val it : int [] = [|9; 13; 17; 21|]

> Array.map (fun x -> x * x) arr;;
val it : int [] = [|1; 25; 81; 169; 289; 441; 625; 841|]

> Array.filter (fun x -> x % 3 = 0) arr;;
val it : int [] = [|9; 21|]

> Array.sort_by string arr;;
val it : unit = ()

> arr;;
val it : int array = [|1; 13; 17; 21; 25; 29; 5; 9|]

> Array.fold_left (fun acc x -> acc + string x + " ") "" arr;;
val it : string = "1 5 9 13 17 21 25 29 "

• Arrays in F# (Marius Bancila)