Why exactly is eval evil?

Question

I know that Lisp and Scheme programmers usually say that eval should be avoided unless strictly necessary. I’ve seen the same recommendation for several program

Answer 1

There have been many great answers but here is another take from Matthew Flatt, one of the implementers of Racket:

http://blog.racket-lang.org/2011/10/on-eval-in-dynamic-languages-generally.html

He makes many of the points that have already been covered but some people may find his take interesting nonetheless.

Summary: The context in which it's used affects the result of eval but is often not considered by programmers, leading to unexpected results.