Learning Ruby

Chapter 4. Strings

In the simplest terms, a string in a programming language is a sequence of one or more characters and usually represents some human language, whether written or spoken. You are probably more likely to use methods from the String class than from any other class in Ruby. Manipulating strings is one of the biggest chores a programmer has to manage. Fortunately, Ruby offers a lot of convenience in this department.

For more information on string methods, go to http://www.ruby-doc.org/core/classes/String.html. You can also use the command line to get information on a method. For example, to get information on the String instance method chop, type:

ri String#chop [or] ri String.chop

You can use # or . between the class and method names when returning two methods with ri. This, of course, assumes that you have the Ruby documentation package installed and that it is in the path (see "Installing Ruby,” in Chapter 1).

Creating Strings

You can create strings with the new method. For example, this line creates a new, empty string called title:

title = String.new # => ""

Now you have a new string, but it is only filled with virtual air. You can test a string to see if it is empty with empty?:

title.empty? # => true

You might want to test a string to see if it is empty before you process it, or to end processing when you run into an empty string. You can also test its length or size:

title.length [or] title.size # => 0

The length and size methods do the same thing: they both return an ...