Anything past the hash tag sign on the same line is a comment.
number = 10 # Assign digit 10 to a number.
Anything included between the =begin and =end is also considered a comment. The =begin or =end must start in the first column.
This is comment
Local Variables: Edit
Local variables exist only within the current programming block.
number1 = 10 # A simple integer
number2 = 112.3412 # Decimal or float as they are called
name = "Captain Cuddles" # Strings are used for storing text.
Instance Variables: Edit
Instance variables (@my_var) are only accessible within the current body scope!
@my_var = 10
@my_other_var = "Hello"
Class Variables: Edit
Class variables (@@my_var) are accessible within the all body scopes and controllers!
@@my_var = 10
@@my_other_var = "Hello"
You may also use getVar('var_name'), setVar('var_name', value).
getVar('count') # <= returns 20
The only difference between class variables and getVar is that an undefined class variable will raise an exception, but an undefined getVar('var_name') will simply return 0. It is recommended to use getVar('var_name') when implementing data between the controllers, as they won't raise any errors.
Another method is getSetVar('var_name', value). What it does is returns original values and assigns the new value.
getSetVar('count', 20) # <= returns 10 (the original value) and assigns 20.
Global Variables: Edit
Global variables ($my_var) are accessible everywhere in the current SketchUp application.
$my_var = 10
$my_other_var = "Hello"
It is recommended to minimize the use of global variables to follow the Ruby scripting rules.
Now if we want to combine text and numbers we need some type conversions, but those are no problem in Ruby.
number1 = "19837".to_i # Converts string (text) into an integer
number2 = "198.37".to_f # Converts text into a float/decimal/numeric.
some_text = "Captain Slow has" + 19837.to_s + "peanuts" # To combine the number with text we converted it to a string.
Random Values: Edit
Gives a random decimal value between 0 and 1.
Gives a whole (integer) random number between 0 and the specified number minus one. For instance, rand(10) will return a whole number between 0 and 9.
See Also: Edit
http://ruby-doc.org/core-1.8.6/ For SU2013 and below
http://ruby-doc.org/core-2.0.0/ For SU2014