Ruby split by whitespace

问题:

How can I write a Ruby function that splits the input by any kind of whitespace, and remove all the whitespace from the result? For example, if the input is

 aa bbb
cc    dd ee

Then return an array ["aa", "bbb", "cc", "dd", "ee"].

回答1:

The following should work for the example you gave:

str.gsub(/\s+/m, ' ').strip.split(" ")

it returns:

["aa", "bbb", "cc", "dd", "ee"]

Meaning of code:

/\s+/m is the more complicated part. \s means white space, so \s+ means one ore more white space letters. In the /m part, m is called a modifier, in this case it means, multiline, meaning visit many lines, not just one which is the default behavior. So, /\s+/m means, find sequences of one or more white spaces.

gsub means replace all.

strip is the equivalent of trim in other languages, and removes spaces from the front and end of the string.

As, I was writing the explanation, it could be the case where you do end up with and end-line character at the end or the beginning of the string.

To be safe

The code could be written as:

str.gsub(/\s+/m, ' ').gsub(/^\s+|\s+$/m, '').split(" ")

So if you had:

str = "\n     aa bbb\n    cc    dd ee\n\n"

Then you'd get:

["aa", "bbb", "cc", "dd", "ee"]

Meaning of new code:

^\s+ a sequence of white spaces at the beginning of the string

\s+$ a sequence of white spaces at the end of the string

So gsub(/^\s+|\s+$/m, '') means remove any sequence of white space at the beginning of the string and at the end of the string.

回答2:

This is the default behavior of String#split:

input = <<-TEXT
 aa bbb
cc    dd ee
TEXT

input.split

Result:

["aa", "bbb", "cc", "dd", "ee"]

This works in all versions of Ruby that I tested, including 1.8.7, 1.9.3, 2.0.0, and 2.1.2.

回答3:

input = <<X
     aa bbb
cc    dd ee
X

input.strip.split(/\s+/)

回答4:

input.split("\s")

If "\s" is used instead of /\s/, whites-paces will be removed from the result.

回答5:

As a slight modification to Vidaica's answer, in Ruby 2.1.1 it looks like

input.split(" ")

Will compensate for all whitespace, be it spaces, tabs, or newlines, yielding:

["aa", "bbb", "cc", "dd", "ee"]