mutable_arrays

string1 = "arrays are mutable"
string2 = "and so are strings"
string3 = "did you know?"

array1 = [string1, string2, string1]

array1[0] << " and so are strings"

array1

# You're probably expecting array1 to return ["arrays are mutable and so are strings", "and so are strings", "arrays are mutable"], right?

# NOPE. The result is:

[
    [0] "arrays are mutable and so are strings",
    [1] "and so are strings",
    [2] "arrays are mutable and so are strings"
]