Truncate string when it is too long

Question

I have two strings:

short_string = \"hello world\"
long_string = \"this is a very long long long .... string\" # suppose more than 10000 chars

Answer 1

First of all, you need a method to truncate a string, either something like:

def truncate(string, max)
  string.length > max ? "#{string[0...max]}..." : string
end

Or by extending String: (it's not recommended to alter core classes, though)

class String
  def truncate(max)
    length > max ? "#{self[0...max]}..." : self
  end
end

Now you can call truncate when printing the string:

puts "short string".truncate
#=> short string

puts "a very, very, very, very long string".truncate
#=> a very, very, very, ...

Or you could just define your own puts:

def puts(string)
  super(string.truncate(20))
end

puts "short string"
#=> short string

puts "a very, very, very, very long string"
#=> a very, very, very, ...

Note that Kernel#puts takes a variable number of arguments, you might want to change your puts method accordingly.