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

In general R coding, both = and <- can assign values to variables, but <- is the conventional operator for assignment, while = is more often used for function arguments. For instance, x <- 10 is a standard assignment, whereas mean(x = c(1,2,3)) is more readable when specifying arguments. That said, you can still do x = 10 in place of x <- 10, and it will work the same way in most contexts.

Function Arguments vs. Assignment
When passing parameters to a function, = is typically used to set argument names and default values. For example:

my_function <- function(a = 5, b = 10) { ... }

Inside or outside functions, <- is a more explicit operator for assigning values to objects, such as my_var <- 42. Using = in a function call clarifies that you’re specifying an argument rather than performing an assignment in the global environment.

Readability and Conventions
Although = and <- usually produce the same outcome in many scripts, <- is widely regarded as more “R-like.” This is largely a style convention. In collaborative settings, sticking to <- for assignment and = for function arguments makes your code more readable and easier to maintain.

Resources for Further Learning
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