Why text processing is common in R Programming - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print the number of words in the text.

R Programming

text <- "Hello world from R"
words <- strsplit(text, [1])[[1]]
print(length(words))

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

A" "

B"."

C","

D"\n"

Attempts:

3 left

💡 Hint

Common Mistakes

Using a comma or period as the separator instead of a space.

Forgetting to use quotes around the separator.

The text is split by spaces to separate words, so the delimiter is a space " ".

2fill in blank

medium

Complete the code to convert all text to lowercase.

R Programming

text <- "Hello World"
lower_text <- [1](text)
print(lower_text)

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

Atolower

Btrimws

Ccapitalize

Dtoupper

Attempts:

3 left

💡 Hint

Common Mistakes

Using toupper() which converts text to uppercase.

Using functions unrelated to case conversion.

tolower() converts all characters in the text to lowercase.

3fill in blank

hard

Fix the error in the code to replace all spaces with underscores.

R Programming

text <- "Hello world from R"
new_text <- gsub([1], "_", text)
print(new_text)

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

A"-"

B"_"

C" "

D"."

Attempts:

3 left

💡 Hint

Common Mistakes

Replacing underscores instead of spaces.

Using the wrong pattern string.

To replace spaces, the pattern to match is a space " ".

4fill in blank

hard

Fill both blanks to create a named vector with word lengths for words longer than 3 characters.

R Programming

words <- c("cat", "elephant", "dog", "giraffe")
lengths <- c([1](words))
names(lengths) <- words
filtered <- lengths[lengths [2] 3]
print(filtered)

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

Anchar

Blength

C>

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using length() which returns the number of elements, not characters.

Using the wrong comparison operator.

nchar() gets the length of each word, and we filter lengths greater than 3.

5fill in blank

hard

Fill all three blanks to create a named vector of uppercase words longer than 4 characters.

R Programming

words <- c("apple", "bat", "carrot", "dog")
upper_words <- toupper([1])
lengths <- nchar([2])
result <- upper_words[lengths [3] 4]
print(result)

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

Awords

Bupper_words

C>

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using upper_words for length calculation which is already uppercase.

Using the wrong comparison operator.

We convert original words to uppercase, get their lengths, and filter those longer than 4.