# Arrays

func main():

    # Arrays are ordered collections of values.
    # You can define an array using `[...]`:

    nums := [10, 20, 30]

    # Arrays are 1-indexed.
    >> nums[2]
    = ???

    # Arrays can be empty but must have a type:
    empty := [:Int]

    >> empty
    = []

    # You can loop over an array with `for value in array`:
    sum := 0
    for num in nums:
        sum += num

    >> sum
    = ???

    # Array comprehensions let you transform arrays concisely:
    squares := [n + 1 for n in nums]

    >> squares
    = [???]

    # You can also get the index with `for index, value in array`:
    for i, num in nums:
        >> squares[i] == num * num
        = yes