Lots of other methods

If you look at the methods that are defined on strings and arrays (e.g. run [].methods.sort or {}.methods.sort in IRB), then you’ll find quite a bunch of method names that look like they are doing exactly what their names describe.

For example, some of the things you can do with strings are:

• "a string".capitalize returns "A string", with the first letter uppercased.
• "a string".length returns 8, which is the length of the string.
• "a string".start_with?("a") returns true, because the string starts with an "a".
• "a string".include?("s") returns true, because the string contains the character "s".

Some examples for useful methods on arrays are:

• [5, 1, 3].sort returns another array, with the elements sorted: [1, 3, 5].
• [5, 1, 3].size returns 3, the number of elements in the array.
• [1, 1, 1, 2].uniq returns a new array with duplicate elements removed: [1, 2].
• [1, 2, 3].join(", ") returns a string "1, 2, 3".
• [1, 2, 3].include?(2) returns true because the array contains the number 2.

How do you find all these methods?

The quickest way to find a certain method for an object often is to just ask Google: “ruby array sort”. That will point you to the Ruby documentation. Another way is to read through all the methods for the class on the respective Ruby documentation page. And of course, you can also read through the method names returned by [1, 2, 3].methods.sort.