Name masking - Preserving definition environment

Namemasking.R

j <- function(x) {
  y <- 2 # Define y
  
  # j returns this function 
  function() {
    c(x, y)
  }
  
}

k <- j(1)
k()

Name Masking

Lexical scoping looks up symbol values based on how functions were nested when they were created, not how they are nested when they are called. With lexical scoping, you don’t need to know how the function is called to figure out where the value of a variable will be looked up. You just need to look at the function’s definition.

Example

This example illustrates a basic principle of lexical scoping. This works because k preserves the environment in which it was defined and because the environment includes the value of y.