Information Technology Reference
In-Depth Information
In Ruby, a variable is accessible within the outermost scope of its declaration. Consider the
following example that better demonstrates variable scope. First, a top-level variable named
bacon_type is declared and assigned the value crispy . Next, the bacon is cooked twice and
an additional variable named temperature is assigned the value 300 . Finally, the script at-
tempts to access the temperature variable, which is now out of scope:
bacon_type = 'crispy'
2 . times ddo
puts bacon_type
temperature = 300
end
end
puts temperature
The bacon_type variable is declared at the top-level scope, so it will be accessible every-
where within this context.
We can access the bacon_type variable inside a more specific scope, such as a loop.
A variable declared inside a scope is accessible only from inside that scope.
Ou tside of the scope of declaration, attempting to access a variable will result in an ex-
ception ( undefined local variable or method 'temperature' ).
WAIT… WHAT ARE YOU SAYING?
It's worth noting that if you're feeling a bit lost at this point, this topic presumes a basic
level of experience with object-oriented programming concepts. If you're not clear about
variables, scope, and loops, you'll probably want to brush up on some of the basics of
object-oriented programming and then head back here to get up to speed on Ruby and
Chef. A great topic on object-oriented programming with Ruby is Practical Object-Ori-
ented Design in Ruby , by Sandi Metz.
 
 
 
 
 
 
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