Ruby

== Local Variables and eval

Using +eval+ to evaluate Ruby code will allow access to local variables in

the same scope, even if if the local variables are not assigned until after

the call to +eval+. However, local variables set inside the call to +eval+

will not be reflected in the surrounding scope. Inside the call to +eval+,

local variables in the scope and local variables defined inside the call to

+eval+ will be accessible. However, you will not be able to access local

variables assigned in previous or subsequent calls to +eval+ in the same

scope. Consider each +eval+ call a separate nested scope. Example:

def m

eval "bar = 1"

lvs = eval "baz = 2; ary = [local_variables, foo, baz]; x = 2; ary"

eval "quux = 3"

foo = 1

lvs << local_variables

end

m

# => [[:baz, :ary, :x, :lvs, :foo], nil, 2, [:lvs, :foo]]