How does R code use Dollar $, and what does it mean? The operator $ is used in R programming to access, add, update, and delete elements from the named list or dataframe. Follow this article to get helpful information.
What is a Dollar in R?
We can add, update, and delete elements and access variables in lists and data frames using the Dollar symbol ($) operator in R.
The examples that follow illustrate typical applications for this operator.
Dollar in R: The Example
Using Dollar to create a variable in a list
First, we need to create a list as shown below:
# Create a list myList <- list( a = c("A", "B", "C"), b = c(12,20), d = 10:20 ) # Print list myList
Output
$a
[1] "A" "B" "C"
$b
[1] 12 20
$d
[1] 10 11 12 13 14 15 16 17 18 19 20
Now, we will use the Dollar to create a variable in the list.
# Create a list myList <- list( a = c("A", "B", "C"), b = c(12,20), d = 10:20 ) myList$e <- c("D","E","F") # Print list myList
Output
$a
[1] "A" "B" "C"
$b
[1] 12 20
$d
[1] 10 11 12 13 14 15 16 17 18 19 20
$e
[1] "D" "E" "F"
You can see that we have a new e-variable in this list.
Using Dollar to access a variable in a list
If you want to access a specific variable in the list, you can use Dollar sign.
Following the code below:
# Create a list myList <- list( a = c("A", "B", "C"), b = c(12,20), d = 10:20 ) # Access b variable myList$b
Output
[1] 12 20
Using Dollar to delete a column in a list
We will access this variable and assign it a NULL value to delete a specific variable in a list.
# Create a list myList <- list( a = c("A", "B", "C"), b = c(12,20), d = 10:20 ) # Delete b variable myList$b <- NULL # Print list myList
Output
$a
[1] "A" "B" "C"
$d
[1] 10 11 12 13 14 15 16 17 18 19 20
Using Dollar to create a variable in a data frame
Similarly, we need to create a dataframe:
# Create a dataframe df <- data.frame( id= 1:5, math = c(8,6,9,7,4), english = c(10,5,7,5,8) ) # Print data frame df
Output
id math english
1 1 8 10
2 2 6 5
3 3 9 7
4 4 7 5
5 5 4 8
Here, we will use Dollar sign to create a variable in this data frame.
# Create a dataframe df <- data.frame( id= 1:5, math = c(8,6,9,7,4), english = c(10,5,7,5,8) ) df$physics <- c(9,7,6,9,8) # Print data frame df
Output
id math english physics
1 1 8 10 9
2 2 6 5 7
3 3 9 7 6
4 4 7 5 9
5 5 4 8 8
Using Dollar to access a variable in a data frame
For instance, the English variable in the data frame can be accessed using the code below:
# Create a dataframe df <- data.frame( id= 1:5, math = c(8,6,9,7,4), english = c(10,5,7,5,8) ) # Access english variable df$english
Output
[1] 10 5 7 5 8
Using Dollar to delete a column in a data frame
To delete a column in a data frame, we will access this column and assign it a NULL value.
# Create a dataframe df <- data.frame( id= 1:5, math = c(8,6,9,7,4), english = c(10,5,7,5,8) ) # Delete english column df$english <- NULL # Print data frame df
Output
id math
1 1 8
2 2 6
3 3 9
4 4 7
5 5 4
Summary
Thank you for reading this article. We hope after reading this article, you will understand more about the dollar in R. If you have any questions, please leave a comment below. We will answer as possible.
Good luck, everyone!
Maybe you are interested:
- %in% Operator In R: The Example Of Operator
- Pipe Operator in R: How to use the pipe operator in R
- OR operator in R: The Usage and Example

Hi, guys! My name’s Scott Miller. My current job is a software developer and I have shared a lot of quality articles about Javascript, C, C++, C#, Python, PHP, R, Java programming languages. I’m hoping they can assist you.
Name of the university: HCMUS
Major: IT
Programming Languages: C, C++, Python, R, Java, JavaScript