Ruby has been described to me as "What Perl 5.5 should have been", but that statement is a severe dis-service to Ruby, and to Perl. Ruby is a new language, and if you're moving into Ruby from Perl, you'll do best not to assume even the basics from Perl. A lot has been learend from Perl, for sure, but that does not mean it has been copied. And the differences start with the fact that in Ruby, everything is an object. With Ruby that goes further too; opearators are really just methods running on the object that's to their left.

Let's see an example in Ruby:

  print "How warm is it today (C) "
  results = gets
  val1 = results.to_i * 9
  val2 = results * 9
  val3 = results.to_f * 9
  puts val1
  puts val2
  puts val3

result:

  munchkin:lruby grahamellis$ ruby nother
  How warm is is today (C) 34
  306
  34
  34
  34
  34
  34
  34
  34
  34
  34
  306.0
  etc

The multiplication method differs ... in Ruby, if I multiply an integer by an integer, I get an integer result. If I multiply a floating point number by an integer, I get a floating point result. And if I multiply a string by an integer, I duplicate that string the number of times given by the integer.

In Perl, the * operator is always numeric and the data is silently converted from a string if necessary, and the x operator provides string replication - converting a number into a string ahead of time if it needs to do so.

The code used above is included in a complete example from the private Ruby Programming Course which I ran last week in Liverpool. Full example source [here]. Picture accompanyng article also from Liverpool - sort of appropriate as I've been examining code in detail in this article.

(written 2012-06-09, updated 2012-06-16)

 R109 - Ruby - Strings and Regular Expressions
  [970] String duplication - x in Perl, * in Python and Ruby - (2006-12-07)
  [986] puts - opposite of chomp in Ruby - (2006-12-15)
  [987] Ruby v Perl - interpollating variables - (2006-12-15)
  [1195] Regular Express Primer - (2007-05-20)
  [1305] Regular expressions made easy - building from components - (2007-08-16)
  [1588] String interpretation in Ruby - (2008-03-21)
  [1875] What are exceptions - Python based answer - (2008-11-08)
  [1887] Ruby Programming Course - Saturday and Sunday - (2008-11-16)
  [1891] Ruby to access web services - (2008-11-16)
  [2293] Regular Expressions in Ruby - (2009-07-16)
  [2295] The dog is not in trouble - (2009-07-17)
  [2608] Search and replace in Ruby - Ruby Regular Expressions - (2010-01-31)
  [2614] Neatly formatting results into a table - (2010-02-01)
  [2621] Ruby collections and strings - some new examples - (2010-02-03)
  [2623] Object Oriented Ruby - new examples - (2010-02-03)
  [2980] Ruby - examples of regular expressions, inheritance and polymorphism - (2010-10-02)
  [3424] Divide 10000 by 17. Do you get 588.235294117647, 588.24 or 588? - Ruby and PHP - (2011-09-08)
  [3621] Matching regular expressions, and substitutions, in Ruby - (2012-02-23)
  [3757] Ruby - a teaching example showing many of the language features in short but useful program - (2012-06-09)
  [4388] Global Regular Expression matching in Ruby (using scan) - (2015-01-08)
  [4505] Regular Expressions for the petrified - in Ruby - (2015-06-03)
  [4549] Clarrissa-Marybelle - too long to really fit? - (2015-10-23)

R103 - Basic Ruby Language Elements
  [2287] Learning to program in Ruby - examples of the programming basics - (2009-07-15)
  [2296] Variable scope - what is it, and how does it Ruby? - (2009-07-18)
  [2613] Constants in Ruby - (2010-02-01)
  [2617] Comparing floating point numbers - a word of caution and a solution - (2010-02-01)
  [3278] Do I need to initialise variables - programming in C, C++, Perl, PHP, Python, Ruby or Java. - (2011-05-05)
  [3430] Sigils - the characters on the start of variable names in Perl, Ruby and Fortran - (2011-09-10)
  [3917] BODMAS - the order a computer evaluates arithmetic expressions - (2012-11-09)
  [4324] Learning to program - variables and constants - (2014-11-22)
  [4369] Ruby - the second rung of learning the language - (2014-12-28)
  [4504] Where does Ruby load modules from, and how to load from current directory - (2015-06-03)

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