Question

In some code I’m trying to learn from, the Maze string below is turned into an array (code not shown for that) and saved in the instance variable @maze. The starting point of the Maze is represented by the letter ‘A’ in that Maze, which can be accessed at @maze[1][13]—row 1, column 13. However, the code I’m looking at uses @maze[1][13,1] to get the A, which you can see returns the same result in my console. If I do @maze[1][13,2], it returns the letter “A ” with two blank spaces next to it, and so on. [13,3] returns “A ” with three blank spaces.

Does the 2 in [13,2] mean, “return two values starting at [1][13]? If so, why? Is this some feature of arrays or two dimensional arrays that I don’t get?

[20] pry(#<Maze>):1> @maze[1][13]
=> "A"
[17] pry(#<Maze>):1> @maze[1][13,1]
=> "A"
[18] pry(#<Maze>):1> @maze[1][13,2]
=> "A "
[19] pry(#<Maze>):1> @maze[1][13,3]
=> "A  "

Maze String

MAZE1 = %{#####################################
# #   #     #A        #     #       #
# # # # # # ####### # ### # ####### #
# # #   # #         #     # #       #
# ##### # ################# # #######
#     # #       #   #     # #   #   #
##### ##### ### ### # ### # # # # # #
#   #     #   # #   #  B# # # #   # #
# # ##### ##### # # ### # # ####### #
# #     # #   # # #   # # # #       #
# ### ### # # # # ##### # # # ##### #
#   #       #   #       #     #     #
#####################################}

Answer 1

From what you show, it seems that @maze is not a two-dimentional array, but is an array of strings. @maze[1] is a string. The second [] is applied to a string. And the second argument of String#[] method describes the length of characters to take. You can consider that it is defaulted to 1 when you do not specify it. By the way, your question is wrong. You describe

If I do @maze[1][13,2], it returns the letter “A ” with two blank spaces next to it, and so on.

but what your example shows is

If I do @maze[1][13,2], it returns the letter “A ” with one blank space next to it, and so on.