What's the difference between "<-" and "<<-" in R? I have read the help file in R. But I still don't understand their difference. Could any one provide an example? Thanks a lot!
Asked
Active
Viewed 123 times
1
-
1From [@kohske's answer](http://stackoverflow.com/questions/9851655/why-is-using-frowned-upon-and-how-can-i-avoid-it/9851794#9851794): "< – talat Jul 25 '14 at 09:05
-
This is not the exact duplicate of @beginneR link, but this should be marked as one so the provided link will educate newbies how to properly use this operator – David Arenburg Jul 25 '14 at 09:12
1 Answers
0
used inside a function, the standard "<-" operator defines a variable inside this function and the variable will not be available outside.
Using "<<-" enables your function to define a variable outside, aka in the global environment, for further use.
That is quite useful in fact!
agenis
- 7,337
- 5
- 44
- 92
-
2Wrong. This should be never used to assign to the global environment. The only good use for it is via lexical scope – David Arenburg Jul 25 '14 at 09:13
-
-
1It will first look in the parent environment and upwards, in case it won't find any, it will create a new one the global environment – David Arenburg Jul 25 '14 at 09:52
-