Step 15: Nil
What happens if we try to access an index that is outside of the array?
my_array = [1, 2, 3, 4, 5] puts(my_array)
There is no value at index 17 in
my_array, and this is exactly what was returned. In Ruby,
nil is an object used to represent the concept of nothing. Variables can be
nil can also be placed in arrays explicitly.
empty_variable = nil empty_array = [nil, nil, nil]
Another important point with
nil is that Ruby treats it as a false value in logical expressions. In Ruby, any object other than
false is treated as a true value (this concept is called truthiness).
if 53 && nil puts("hi") else puts("bye") end puts(nil == false)
Here we can see that
false are not equivalent, but in the
if clause the
nil does the same thing as
false in the case of the logical expression.