Ruby How to get the first character of a string

Question

How can I get the first character in a string using Ruby   Ultimately what I m doing is taking someone s last name and just creating an initial out of it   So if the string was  Smith  I just want  S

User · Answer

Any of these methods will work   name    Smith  puts name  0  0      gt  S puts name  0      gt  S puts name  0 1      gt  S puts name  0  chr     gt  S

User · Answer

Smith  0  0    works in both ruby 1 8 and ruby 1 9

User · Answer

In MRI 1 8 7 or greater    foobarbaz  each char first

User · Answer

Because of an annoying design choice in Ruby before 1 9     some string 0  returns the character code of the first character     the most portable way to write this is some string 0 1   which tells it to get a substring at index 0 that s 1 character long

User · Answer

In Rails  name    Smith  name first

User · Answer

If you use a recent version of Ruby  1 9 0 or later   the following should work    Smith  0      gt   S    If you use either 1 9 0  or 1 8 7  the following should work    Smith  chars first     gt   S    If you use a version older than 1 8 7  this should work    Smith  split     first     gt   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

User · Answer

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

User · Answer

gt  gt  s    Smith                                                              gt   Smith                                                                 gt  gt  s 0                                                                     gt   S

User · Answer

You can also use truncate   gt   Smith  truncate 1  omission         gt   S    or for additional formatting    gt   Smith  truncate 4     gt   S       gt   Smith  truncate 2  omission          gt   S

User · Answer

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       gt   S    http   ruby-doc org core-1 9 3 String html method-i-chr

User · Answer

Another option that hasn t been mentioned yet    gt   Smith  slice 0     gt   S

User · Answer

Try this    gt  gt  a    Smith   gt  gt  a 0    gt   S    OR   gt  gt   Smith  chr    gt   S

User · Answer

Try this  def word string  num      string    Smith      string 0   num-1   end

[ruby] Ruby: How to get the first character of a string

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