print([])
print([1, 2, 3])
print([1, '2', 3, ])
print([1, [2, 3], 4])
print([1, [2, [3, 4]], 5])

let a := [1, 2, 3]
print(a[2])
print(a?.[2])
print(a?.2)
print(a?.[7])
print(a?.7)
print([1, 2, 3][2], )
print([1, [2, [3, 4], ], 5][2][2][2])
print([1, [2, [3, 4], ], 5]?.2?.2?.2)
print([1, [2, [3, 4], ], 5]?.[2]?.[2]?.[2])
print([1, [2, [3, 4], ], 5]?.7?.4?.2)
print([1, [2, [3, 4], ], 5]?.[7]?.[4]?.[2])
print([1, [2, [3, 4]], 5][2][2][2] + 1)
print([1, [2, [3, 4, ], ], 5, ].2.2.2)

print('------')
let b := [1, 2, [1,2,3]]
b[2] := 4
print(b[1])
print(b[2])
print(b[3])
b[3][3] := 8
print(b)

print('------')

print(arrayPushBack([1,2,3], 4))
print(arrayPushFront([1,2,3], 0))
print(arrayPopBack([1,2,3]))
print(arrayPopFront([1,2,3]))
print(arraySort([3,2,1]))
print(arrayReverse([1,2,3]))
print(arrayReverseSort([3,2,1]))
print(arrayStringConcat([1,2,3], ','))

print('-----')
let arr := [1,2,3,4]   // we don't modify arr
print(arr)
arrayPushBack(arr, 5)
print(arr)
arrayPushFront(arr, 0)
print(arr)
arrayPopBack(arr)
print(arr)
arrayPopFront(arr)
print(arr)
arraySort(arr)
print(arr)
arrayReverse(arr)
print(arr)
arrayReverseSort(arr)
print(arr)