If you want to pass a block of code into a Ruby procedure, you can do so by passing in the code to a variable who's name you start with an & in the procedure definition; you can then run that code using the .call method on the received object. In some ways this is an indirect reference - in Ruby you can's simply assign code to a variable.

You can also pass a curly brace defined block / closure into a procedure by specifying it as the piece of code that the procedure should jump to when it encounters a yield.

There are examples of both of these syntaxes at [this location].

(written 2010-02-02)

 R104 - Ruby - Control Structures
  [960] 1st, 2nd, 3rd revisited in Ruby - (2006-12-02)
  [962] Breaking a loop - Ruby and other languages - (2006-12-03)
  [985] Equality in Ruby - == eql? and equal? - (2006-12-14)
  [995] Ruby's case - no break - (2006-12-17)
  [1163] A better alternative to cutting and pasting code - (2007-04-26)
  [1220] for loop - how it works (Perl, PHP, Java, C, etc) - (2007-06-06)
  [1582] Ruby, C, Java and more - getting out of loops - (2008-03-19)
  [1587] Some Ruby programming examples from our course - (2008-03-21)
  [1696] Saying NOT in Perl, PHP, Python, Lua ... - (2008-07-04)
  [1738] Clean code, jump free (Example in Lua) - (2008-08-06)
  [1870] What to do with a huge crop of apples - (2008-11-04)
  [1887] Ruby Programming Course - Saturday and Sunday - (2008-11-16)
  [1891] Ruby to access web services - (2008-11-16)
  [1904] Ruby, Perl, Linux, MySQL - some training notes - (2008-11-23)
  [2287] Learning to program in Ruby - examples of the programming basics - (2009-07-15)
  [2471] A short form of if ... then ... else - (2009-10-23)
  [2711] For loop - checked once, or evety time? Ruby v Perl comparison and contrast - (2010-04-07)
  [2892] Alternative loops and conditionals in Ruby and Perl - (2010-07-28)
  [2975] Why do I need brackets in Ruby ... or Perl, Python, C or Java - (2010-09-29)
  [3156] Splitting data reading code from data processing code - Ruby - (2011-02-04)
  [3158] Ruby training - some fresh examples for string handling applications - (2011-02-05)
  [3159] Returning multiple values from a function call in various languages - a comparison - (2011-02-06)
  [3200] How a for loop works Java, Perl and other languages - (2011-03-12)
  [3253] Is this number between? Does this list include? - Ruby - (2011-04-18)
  [3254] Multiple inputs, multiple out, ruby functions - (2011-04-19)
  [3397] Does a for loop evaluate its end condition once, or on every iteration? - (2011-08-18)
  [3422] Assigning values to variables within other statements - Ruby - (2011-09-07)
  [3619] Ruby v Perl - a comparison example - (2012-02-21)
  [3620] Finding the total, average, minimum and maximum in a program - (2012-02-22)
  [3769] Muttable v immutable and implications - Ruby - (2012-06-20)
  [4322] Learning to Program - the conditional statement (if) - (2014-11-21)
  [4323] Learning to program - Loop statements such as while - (2014-11-22)
  [4370] Conditionals, loops and methods in Ruby - a primer with simple examples - (2014-12-29)
  [4402] Finding sum, minimum, maximum and average in Python (and Ruby) - (2015-01-19)
  [4503] Separating your code for easier testing, understanding and re-use; example in Ruby - (2015-06-02)
  [4504] Where does Ruby load modules from, and how to load from current directory - (2015-06-03)
  [4674] Alternating valuses / flip-flop / toggle - example in Ruby - (2016-05-17)

Back to What are Ruby Symbols?

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Forward to Direct access to object variable (attributes) in Ruby

Object Oriented Ruby - new examples
Handling unusual and error conditions - exceptions
Ruby collections and strings - some new examples
Direct access to object variable (attributes) in Ruby
Passing code to procedures and yield in Ruby
What are Ruby Symbols?
Comparing floating point numbers - a word of caution and a solution
Defining a static method - Java, Python and Ruby
String to number conversion with error trapping in Ruby
Neatly formatting results into a table