How to conditionally replace values in r data frame using if/then statement

Question

I\'d like to learn how to conditionally replace values in R data frame using if/then statements. Suppose I have a data frame like this one:

df <- data.fra         


        

Answer 1

You are using == instead of =(Assignment Operator) in if block. And I dont think there's need of else block in your example as you are not going to change values

 if(df$customer %in% c('paramount','pixar')){
  df$customer_id = 99
 }

Above code will do the job for you

Answer 2

You can use ifelse, like this:

df$customer_id <- ifelse(df$customer %in% c('paramount', 'pixar'), 99, df$customer_id)

The syntax is simple:

ifelse(condition, result if TRUE, result if FALSE)

This is vectorized, so you can use it on a dataframe column.