Excel files with readxl in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to load the readxl package.

R Programming

library([1])

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

Areadxl

Bggplot2

Ctidyr

Ddplyr

Attempts:

3 left

💡 Hint

Common Mistakes

Loading a different package like dplyr or ggplot2 instead of readxl.

The readxl package is used to read Excel files in R. You load it with library(readxl).

2fill in blank

medium

Complete the code to read an Excel file named 'data.xlsx'.

R Programming

df <- read_excel([1])

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

Adata.csv

B'data.csv'

Cdata.xlsx

D'data.xlsx'

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes around the file name.

Using the wrong file extension like .csv instead of .xlsx.

The file name must be a string, so it needs quotes: 'data.xlsx'.

3fill in blank

hard

Fix the error in the code to read the second sheet of an Excel file.

R Programming

df <- read_excel('data.xlsx', sheet = [1])

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

A'2'

B'Sheet2'

C2

DSheet2

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes around the sheet number.

Using the sheet name without quotes or with wrong quotes.

The sheet argument can be a number without quotes to specify the sheet index.

4fill in blank

hard

Fill both blanks to read only the first 5 rows and skip the first row of an Excel sheet.

R Programming

df <- read_excel('data.xlsx', n_max = [1], skip = [2])

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

A5

B1

C10

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing the values for n_max and skip.

Using zero for skip when the first row should be skipped.

n_max = 5 reads only 5 rows, and skip = 1 skips the first row.

5fill in blank

hard

Fill all three blanks to read an Excel file, select the sheet named 'Data', and convert column names to lowercase.

R Programming

df <- read_excel('data.xlsx', sheet = [1])
names(df) <- tolower([2])
print(head([3]))

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

A'Data'

Bnames(df)

Cdf

D'Sheet1'

Attempts:

3 left

💡 Hint

Common Mistakes

Using sheet index instead of sheet name.

Not using quotes around sheet name.

Trying to convert names of a wrong object.

Use sheet = 'Data' to select the sheet by name. Then convert column names with names(df). Finally, print the first rows of df.

Practice

1. What is the primary purpose of the readxl package in R?

easy

A. To convert Excel files to CSV format

B. To write Excel files from R data frames

C. To read Excel files (.xls, .xlsx) into R data frames

D. To create Excel charts from R data

Solution

1. Step 1: Understand the purpose of readxl

   The readxl package is designed to import Excel files into R as data frames.

2. Step 2: Differentiate from other packages

   It does not write files or create charts; it only reads Excel files.

3. Final Answer:

   To read Excel files (.xls, .xlsx) into R data frames -> Option C

4. Quick Check:

   readxl = read Excel files [OK]

Hint: Remember: readxl reads Excel files into R [OK]

Common Mistakes:

• Confusing readxl with packages that write Excel files
• Thinking readxl creates charts
• Assuming readxl converts files to CSV

2. Which of the following is the correct syntax to read the first sheet of an Excel file named data.xlsx using readxl?

easy

A. read_excel(1, "data.xlsx")

B. read_excel("data.xlsx", sheet = 1)

C. read_excel("data.xlsx", sheet = "first")

D. read_excel("data.xlsx", sheet = TRUE)

Solution

1. Step 1: Check the function syntax

   The function read_excel() takes the file path as the first argument, then optional parameters like sheet.

2. Step 2: Validate sheet argument

   Sheet can be specified by number (1) or name (string). read_excel("data.xlsx", sheet = 1) uses sheet = 1 correctly.

3. Final Answer:

   read_excel("data.xlsx", sheet = 1) -> Option B

4. Quick Check:

   File path first, then sheet number [OK]

Hint: File path first, sheet number second in read_excel() [OK]

Common Mistakes:

• Swapping argument order
• Using invalid sheet names like "first"
• Passing TRUE instead of sheet number or name

3. What will be the output of this R code snippet using readxl?

library(readxl)
data <- read_excel("file.xlsx", range = "B2:D4")
print(dim(data))

medium

A. [1] 3 3

B. [1] 4 3

C. [1] 3 4

D. [1] 4 4

Solution

1. Step 1: Understand the range argument

   The range "B2:D4" selects columns B to D (3 columns) and rows 2 to 4 (3 rows).

2. Step 2: Determine dimensions of the data frame

   So the data frame will have 3 rows and 3 columns.

3. Final Answer:

   [1] 3 3 -> Option A

4. Quick Check:

   Range B2:D4 = 3 rows x 3 columns [OK]

Hint: Count rows and columns in range like Excel cells [OK]

Common Mistakes:

• Counting rows or columns incorrectly
• Confusing row and column order
• Assuming range includes headers automatically

4. Identify the error in this code snippet that tries to read the sheet named "Sales" from report.xlsx:

library(readxl)
data <- read_excel("report.xlsx", sheet = Sales)

medium

A. Sheet name must be a string in quotes

B. File path should not be in quotes

C. read_excel does not support sheet argument

D. Missing library call for readxl

Solution

1. Step 1: Check sheet argument type

   The sheet argument expects a string for sheet name, so it must be in quotes like "Sales".

2. Step 2: Verify other parts

   File path is correctly quoted, readxl supports sheet argument, and library is loaded.

3. Final Answer:

   Sheet name must be a string in quotes -> Option A

4. Quick Check:

   Sheet names need quotes [OK]

Hint: Put sheet names inside quotes in read_excel() [OK]

Common Mistakes:

• Forgetting quotes around sheet names
• Removing quotes from file path
• Not loading readxl library

5. You want to read only the cells from columns C to E and rows 5 to 10 in the sheet named "Data" from records.xlsx. Which code correctly does this using readxl?

hard

A. read_excel("records.xlsx", sheet = "Data", range = "5:10")

B. read_excel("records.xlsx", sheet = Data, range = "C5:E10")

C. read_excel("records.xlsx", range = "C5:E10")

D. read_excel("records.xlsx", sheet = "Data", range = "C5:E10")

Solution

1. Step 1: Specify sheet name correctly

   The sheet name "Data" must be a string in quotes.

2. Step 2: Use correct range format

   The range "C5:E10" selects columns C to E and rows 5 to 10, exactly what is needed.

3. Step 3: Confirm all arguments present

   read_excel("records.xlsx", sheet = "Data", range = "C5:E10") includes file path, sheet name, and range correctly.

4. Final Answer:

   read_excel("records.xlsx", sheet = "Data", range = "C5:E10") -> Option D

5. Quick Check:

   Sheet name + range in quotes = correct [OK]

Hint: Use sheet and range as strings in read_excel() [OK]

Common Mistakes:

• Omitting quotes around sheet name
• Using incomplete range like "5:10"
• Not specifying sheet when multiple sheets exist