Ruby: How to Get the First Character of a String

Ruby: How to get the first character of a string

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] 

Find the first character in an array string

You could change all of the elements of the array to strings then do what you were originally doing.

string = ["A", "B", 1234, 54321]
string.map { |x| x.to_s }[3].chars.first
=> "5"

Ruby: return the first character from string if it matches and if there is no match then return nil?

Use String#[match_str]:

If a match_str is given, that string is returned if it occurs in the string.

Returns nil if (...) the match string cannot be found.

'word'['o'] #=> 'o'
'word'['q'] #=> nil

The [] method is very versatile, you can also pass a regular expression or indices in different ways.

Ruby - How to select some characters from string

Try foo[0...100], any range will do. Ranges can also go negative. It is well explained in the documentation of Ruby.

ruby/regex getting the first letter of each word

You could simply use split, map and join together here.

string = 'I need help'
result = string.split.map(&:first).join
puts result  #=> "Inh"

How do I repeat the first character of words in a string?

You can just split the string by each space, and multiply the first character the number of times you need, then append, or concatenate the "initial" word:

p "abc def".split.map { |word| "#{word[0] * 10}#{word}" }.join(' ')

How to get the first letter of each word

Here is a method I wrote.

def first_chars
  final_string = ""

  self.split(" ").each do |word|
    final_string += word.chr
  end

  return final_string
end

You would use this instead like "hello world".first_chars, which would return hw.

What this does is: splits the given string, self, by spaces into an array. Then it adds the first letter of that word using the .chr method in the .each loop, appends that letter to a string that ends up getting returned.

It could be shortened like this:

def first_chars 
   final_string = ""
   self.split(" ").each { |word| final_string += word.chr }
   return final_string
end

Ruby: getting character[n] from each element of an array of strings, strictly with array notation

I don't believe there is a way to do what you want, but you could do the following.

str = %w(greater yellow bandicooot).join(' ')
  #=> "greater yellow bandicooot"

str.gsub(/(?<=\S)./, '')
  #=> "gyb"

The regular expression matches any character that is preceded by a non-whitespace character; that is, it matches all characters other than the first character of the string and characters preceded by a whitespace character.

If one is given the string and there could be multiple spaces between words, one could write:

str.squeeze(' ').gsub(/(?<=\S)./, '')

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