select() for column selection in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select the column 'mpg' from the mtcars dataset using dplyr's select().

R Programming

library(dplyr)
selected_data <- mtcars %>% select([1])
print(selected_data)

Drag options to blanks, or click blank then click option'

Acyl

Bmpg

Cgear

Dhp

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing a column name that is not in the dataset.

Using quotes around the column name inside select(), which is not needed in tidyverse syntax.

The select() function chooses columns by their names. Here, we want to select the 'mpg' column.

2fill in blank

medium

Complete the code to select columns 'mpg' and 'cyl' from mtcars using select() with the colon operator.

R Programming

library(dplyr)
selected_data <- mtcars %>% select([1])
print(selected_data)

Drag options to blanks, or click blank then click option'

Ampg:cyl:gear

Bmpg,cyl

Cmpg:cyl

Dmpg-cyl

Attempts:

3 left

💡 Hint

Common Mistakes

Using commas inside select() without c(), which is not correct in tidyverse select.

Using dashes or extra colons which are invalid syntax.

The colon operator mpg:cyl selects all columns from 'mpg' to 'cyl' inclusive in their order in the dataset.

3fill in blank

hard

Fix the error in the code to select columns 'mpg' and 'hp' from mtcars using select().

R Programming

library(dplyr)
selected_data <- mtcars %>% select([1])
print(selected_data)

Drag options to blanks, or click blank then click option'

Ampg, hp

B"mpg", "hp"

Cc(mpg, hp)

Dmpg hp

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around column names inside select().

Using c() to combine columns inside select(), which is not needed.

In select(), column names are unquoted and separated by commas without c(). So mpg, hp is correct.

4fill in blank

hard

Fill both blanks to select columns from 'mpg' to 'hp' and exclude 'cyl' from mtcars.

R Programming

library(dplyr)
selected_data <- mtcars %>% select([1]) %>% select(-[2])
print(selected_data)

Drag options to blanks, or click blank then click option'

Ampg:hp

Bcyl

Cgear

Dhp

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to exclude columns before selecting the range.

Not using the minus sign to exclude a column.

First, select columns from 'mpg' to 'hp' using mpg:hp. Then exclude 'cyl' by using -cyl.

5fill in blank

hard

Fill all three blanks to select columns starting with 'd' and ending with 'q' and exclude 'drat' from mtcars.

R Programming

library(dplyr)
selected_data <- mtcars %>% select(starts_with([1]), ends_with([2])) %>% select(-[3])
print(selected_data)

Drag options to blanks, or click blank then click option'

A"d"

B"q"

Cdrat

Dgear

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes inside starts_with or ends_with.

Trying to exclude columns without the minus sign.

Use starts_with("d") and ends_with("q") to select columns starting and ending with those letters. Then exclude 'drat' with -drat.