Question

Bit of an odd question but I want to do something like:

a = 6
b = 12

cond = "((a > 5 and b > 10) or a > 50)" #user generated

if cond
  #do something
end

How can I parse the string, substitute the variables and run as a conditional.

Answer 1

Once you have a Ruby string cond, you can just do eval(cond). But be aware that people will criticize this for security reasons.

By the way, if you actually do eval(cond) to your code, it will return an error because the string cond in your example is not a valid Ruby code.