Dynamically set local variables in Ruby [duplicate]

by

As an additional information for future readers, starting from ruby 2.1.0 you can using binding.local_variable_get and binding.local_variable_set:

def foo
  a = 1
  b = binding
  b.local_variable_set(:a, 2) # set existing local variable `a'
  b.local_variable_set(:c, 3) # create new local variable `c'
                              # `c' exists only in binding.
  b.local_variable_get(:a) #=> 2
  b.local_variable_get(:c) #=> 3
  p a #=> 2
  p c #=> NameError
end

As stated in the doc, it is a similar behavior to

binding.eval("#{symbol} = #{obj}")
binding.eval("#{symbol}")

More Related Contents:

  1. How to call methods dynamically based on their name? [duplicate]
  2. Get the name of the currently executing method
  3. Executing code for every method call in a Ruby module
  4. Why is `a = a` `nil` in Ruby?
  5. Ruby: Inherit code that works with class variables
  6. Calling a Method From a String With the Method’s Name in Ruby
  7. Ruby – print the variable name and then its value
  8. What does send() do in Ruby?
  9. How do I use define_method to create class methods?
  10. Is there a hook similar to Class#inherited that’s triggered only after a Ruby class definition?
  11. Can I dynamically call a math operator in Ruby?
  12. Ruby local variable is undefined
  13. Is it possible to have Methods inside Methods?
  14. Convert array of 2-element arrays into a hash, where duplicate keys append additional values
  15. Ruby: Proc#call vs yield
  16. What is the use case for Ruby’s %q / %Q quoting methods?
  17. Mountain Lion rvm install 1.8.7 x11 error
  18. How to install ruby-debug when needing necessary libraries and/or headers
  19. How do methods use hash arguments in Ruby?
  20. How to cleanly initialize attributes in Ruby with new?
  21. Ruby dependency injection libraries
  22. How can I get the absolute URL when extracting links using Nokogiri?
  23. In Ruby why won’t `foo = true unless defined?(foo)` make the assignment?
  24. Method and variable name is the same
  25. How to determine if a character is a Chinese character
  26. How to turn a string into a method call? [duplicate]
  27. What does the unary question mark (?) operator do?
  28. What is the behavior when using both positional and keyword arguments in Ruby?
  29. Should I use alias or alias_method?
  30. Combine two Arrays into Hash

Leave a Comment