/programming-univbasics-4-array-join-and-string-split-readme

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String's Split Method, Word Array Literal, and Array's Join Method

Learning Goals

  • Join elements of an Array with join to produce a String
  • Create an Array of words with Ruby's %w[] literal
  • Split a String into an Array of words

Introduction

At this point in our journey, we're probably really keen to get some more data than just plain old numbers. It's a good time to cover to methods that are inverses of each other:

  • String's split
  • Array's join

Join Elements of an Array With join to Produce a String

Since we're in a module about Arrays, let's talk about joining an Array of words.

["This", "is", "a", "test"].join(' ') #=> "This is a test"
["This", "is", "a", "test"].join('_') #=> "This_is_a_test"
["This", "is", "a", "test"].join('*') #=> "This*is*a*test"

For more details, consult the join documentation.

Create an Array of Words with Ruby's %w// Literal

Creating an Array of words can be difficult to type with all those " characters rolling about. Ruby invented an operator called the Array of Words literal.

%w[this is also a test] #=> ["this", "is", "also", "a", "test"]
# For method-chaining fun:
%w[this is also a test].join(" ").capitalize #=> "This is also a test"

Split a String into an Array of words

If Array's join can turn an Array of Strings into one String, we can reverse the process with String's split method:

"When in the course of human events".split(" ") #=> ["When", "in", "the", "course", "of", "human", "events"]

Here is a bit of Thomas Jefferson's Declaration of Independence.

Conclusion

These methods and the Array word literal are tools to help you accomplish programming tasks when working with text. There's a lot more to learn, but these are a good start.

Resources