ruby - simplify string multiply concatenation

问题

s is a string, This seems very long-winded - how can i simplify this? :

   if x === 2
      z = s
    elsif x === 3
      z = s+s
    elsif x === 4
      z = s+s+s
    elsif x === 5
      z = s+s+s+s
    elsif x === 6
      z = s+s+s+s+s

Thanks

回答1:

Something like this is the simplest and works (as seen on ideone.com):

puts 'Hello' * 3   # HelloHelloHello

s = 'Go'
x = 4
z = s * (x - 1)
puts z             # GoGoGo

API links

ruby-doc.org - String: str * integer => new_str

Copy—Returns a new String containing integer copies of the receiver.

"Ho! " * 3   #=> "Ho! Ho! Ho! "

回答2:

z=''
(x-1).times do
 z+=s
end

回答3:

Pseudo code (not ruby)

if 1 < int(x) < 7  then
   z = (x-1)*s

回答4:

For example for a rating system up to 5 stars you can use something like this:

def rating_to_star(rating)
   'star' * rating.to_i + 'empty_star' * (5 - rating.to_i)
end

来源：https://stackoverflow.com/questions/3179083/ruby-simplify-string-multiply-concatenation