Other Useful Methods

Below are some array methods you may find useful for problem solving. There's no need to memorize. You'll learn by putting these methods into practice.

You've already seen length in action. It returns the number of elements in the array.

sort sorts an array alphabetically or numerically. It requires that the array be comprised entirely of numbers or strings. Otherwise the interpreter won't know how to compare elements! Like many array methods, sort has a counterpart that modifies the original array: sort!. A bang (!) typically denotes methods that modify their receiver, so-called "dangerous" methods.

reverse reverses the order of an array. reverse has a dangerous version: reverse!.

include? returns a boolean value indicating whether its argument is included in the array.