# let array1 = [|1; 2; 3|];;
val array1 : int array = [|1; 2; 3|]
# let array2 = [|4; 5; 6|];;
val array2 : int array = [|4; 5; 6|]
# let array1and2 = Array.append array1 array2;;
val array1and2 : int array = [|1; 2; 3; 4; 5; 6|]