Ruby: How to get the first character of a string

If you use a recent version of Ruby (1.9.0 or later), the following should work:

'Smith'[0] # => 'S'

If you use either 1.9.0+ or 1.8.7, the following should work:

'Smith'.chars.first # => 'S'

If you use a version older than 1.8.7, this should work:

'Smith'.split(//).first # => 'S'

Note that 'Smith'[0,1] does not work on 1.8, it will not give you the first character, it will only give you the first byte.

For completeness sake, since Ruby 1.9 String#chr returns the first character of a string. Its still available in 2.0 and 2.1.

"Smith".chr    #=> "S"

http://ruby-doc.org/core-1.9.3/String.html#method-i-chr

"Smith"[0..0]

works in both ruby 1.8 and ruby 1.9.

You can use Ruby's open classes to make your code much more readable. For instance, this:

class String
  def initial
    self[0,1]
  end
end

will allow you to use the initial method on any string. So if you have the following variables:

last_name = "Smith"
first_name = "John"

Then you can get the initials very cleanly and readably:

puts first_name.initial   # prints J
puts last_name.initial    # prints S

The other method mentioned here doesn't work on Ruby 1.8 (not that you should be using 1.8 anymore anyway!--but when this answer was posted it was still quite common):

puts 'Smith'[0]           # prints 83

Of course, if you're not doing it on a regular basis, then defining the method might be overkill, and you could just do it directly:

puts last_name[0,1]