Accessing variables of a data frame in R Programming - attach() and detach() function

In this article, we will see how to Access variables of a data frame in R Programming Language.

R - Accessing variables of a data frame

Method 1: Using attach() function in R

attach() function in R Language is used to access the variables present in the data framework without calling the data frame.

Syntax: attach(data, pos)

Parameters: 

• data: data frame
• pos: position of database

Example: Accessing variables of a data frame in R using attach() function

# R program to illustrate
# attach function

# Create example data
data <- data.frame(x1 = c(1, 2, 3, 4, 5),        
                x2 = c(6, 7, 8, 9, 0),
                x3 = c(1, 2, 5, 4, 5))

# Try to print x1
# Error: object 'x1' not found

# attach data
attach(data, pos = x1)                                            

Output: 

1 2 3 4 5

Here in the above code, we have created a data framework and assigned a value to it, when we tried to return value an error occurred. Then we use the attach function and returned value of x1.

Method 2: Using detach() Function

detach() function is used to remove the attachment in data framework that was made by attach() function.

Syntax: detach(data, unload)

Parameters: 

• data: data frame
• unload: boolean value

Example: Accessing variables of a data frame in R using detach() Function 

# R program to illustrate
# detach function

# Install dplyr package
install.packages("dplyr")

# attach dplyr
library("dplyr")                                

# Apply as.tbl function of dplyr package
data_tbl <- as.tbl(data)                        

detach("package:dplyr", unload = FALSE)

# Apply as.tbl after detaching dplyr package
data_tbl <- as.tbl(data)

Output: 

Error in as.tbl(data) : could not find function "as.tbl"

Here in the above code, we have installed a dplyr package and used its function as.tbl. Then we detach the package and try to use the function again, and an error occurred. detach functions are used to unpack the libraries which were added to the library.