Evaluate expression given as a string

Question

I\'m curious to know if R can use its eval() function to perform calculations provided by e.g. a string.

This is a common case:

eval(\"5         


        

Answer 1

Not sure why no one has mentioned two Base R functions specifically to do this: str2lang() and str2expression(). These are variants of parse(), but seem to return the expression more cleanly:

eval(str2lang("5+5"))

# > 10
  
eval(str2expression("5+5"))

# > 10

Also want to push back against the posters saying that anyone trying to do this is wrong. I'm reading in R expressions stored as text in a file and trying to evaluate them. These functions are perfect for this use case.