Ruby: Merging variables in to a string

Question

I\'m looking for a better way to merge variables into a string, in Ruby.

For example if the string is something like:

\"The animal action<

Answer 1

You can use sprintf-like formatting to inject values into the string. For that the string must include placeholders. Put your arguments into an array and use on of these ways: (For more info look at the documentation for Kernel::sprintf.)

fmt = 'The %s %s the %s'
res = fmt % [animal, action, other_animal]  # using %-operator
res = sprintf(fmt, animal, action, other_animal)  # call Kernel.sprintf

You can even explicitly specify the argument number and shuffle them around:

'The %3$s %2$s the %1$s' % ['cat', 'eats', 'mouse']

Or specify the argument using hash keys:

'The %{animal} %{action} the %{second_animal}' %
  { :animal => 'cat', :action=> 'eats', :second_animal => 'mouse'}

Note that you must provide a value for all arguments to the % operator. For instance, you cannot avoid defining animal.