What's the difference between `=` and `<-` in R?

r assignment-operator variable-assignment
Mehper C. Palavuzlar picture Mehper C. Palavuzlar · Feb 16, 2010 · Viewed 84.6k times · Source

I'm using R 2.8.1 and it is possible to use both = and <- as variable assignment operators. What's the difference between them? Which one should I use?

Answer

Mark Byers picture Mark Byers · Feb 16, 2010

From here:

The operators <- and = assign into the environment in which they are evaluated. The operator <- can be used anywhere, whereas the operator = is only allowed at the top level (e.g., in the complete expression typed at the command prompt) or as one of the subexpressions in a braced list of expressions.

Related questions

What are the differences between "=" and "<-" assignment operators in R?

What are the differences between the assignment operators = and <- in R? I know that operators are slightly different, as this example shows x <- y <- 5 x = y = 5 x = y <- 5 x <- y = 5 # …

Read More
Understanding exactly when a data.table is a reference to (vs a copy of) another data.table

I'm having a little trouble understanding the pass-by-reference properties of data.table. Some operations seem to 'break' the reference, and I'd like to understand exactly what's happening. On creating a data.table from another data.table (via <-, then …

Read More
Assign multiple objects to .GlobalEnv from within a function

A post on here a day back has me wondering how to assign values to multiple objects in the global environment from within a function. This is my attempt using lapply (assign may be safer than <<- but …

Read More