switch out variable name using function argument in r

Question

I want to build a function that takes a variable name as an argument so if I have some code like:

function(df, variable = NULL) {
  df <- df %>% filter(variable > 10)
  test <- c()
  for (i in c(1:10)) {
    test2 <- df$variable[i] - df$othervariable[i]
    test <- c(test, test2)
  }
  return(test)
}

Then I can swap out the variable simply by plugging in the name through the argument. I've thought about doing it like df['variable'] instead. But this does not solve the problem in the dplyr filter function and also it returns a dataframe rather than df$variable which is numeric.

Answer 1

df$variable与df[,'variable'] （相同,很重要）相同，也与df[['variable']]