格式化字符串

numbers=[1,2,3, 4,5,6, 7,8,9, 0]

def createPhoneNumber(numbers)  "(#{numbers[0..2].join}) #{numbers[3..5].join}-#{numbers[6..9].join}"endIf you don't mind passing in a 10-character string instead, you can do
def createPhoneNumber( p )    '(%s) %s-%s' % [p[0,3],p[3,3],p[6,4]]    end
Example:
createPhoneNumber('1234567890') # => "[phone]"