Here's something interesting about arrays: each element in the array has what's called an index. The first element gets index 0, the next gets index 1, the one after that gets index 2, and so on. We can access elements of the array directly through these numbers, like so:

array = [5, 7, 9, 2, 0]
array[2]
# returns "9", since "9"
# is at index 2

The diagram below shows how these indices work for our sample array, [5, 7, 9, 2, 0]. The first element gets index 0, the next gets 1, the next gets 2, and so on.

+---+---+---+---+---+
array | 5 | 7 | 9 | 2 | 0 |
+---+---+---+---+---+
index | 0 |1 | 2 | 3 | 4 |

(This is a bit of an oversimplification, but it gets the idea across for now.)

We can access the ith element of an array called array by putting the index in square brackets, like so: array[i]. array[0] gets the first element, array[1] gets the second element, and so on. This is called access by index.

Instructions

Use square bracket notation to print the third value of demo_array to the console.

Remember that the third value is at index two, not at index three. We start counting indices from zero.

demo_array = [100, 200, 300, 400, 500]

print demo_array[2] # Add your code here!

	Created by Austin Rowsell almost 9 years ago

Programming Note on Ruby (Code Academy), created by Austin Rowsell on 27/06/2017.

Ruby (Code Academy)