Lots of Other Methods
Learn how to look up lots of useful methods that we can use in our everyday Ruby code.
We'll cover the following
Names of methods reflect their behavior
If we look at the methods defined on strings, arrays, or hashes (run [].methods.sort
or {}.methods.sort
), then we’ll find many method names that look like they’re doing exactly what their names describe.
For example, some of the things we can do with strings are:
-
"a string".capitalize
returns"A string"
, with the first letter uppercase. -
"a string".length
returns8
, which is the length of the string. -
"a string".start_with?("a")
returnstrue
because the string starts with an"a"
. -
"a string".include?("s")
returnstrue
because the string contains the character"s"
.
Similarly, 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
returns3
, 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)
returnstrue
because the array contains the number2
.
How do we find all these methods?
The quickest way to find a specific method for an object is to search for “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. We can also read through the method names returned by [1, 2, 3].methods.sort
.