paste and paste0 in R Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of paste with default separator

What is the output of this R code snippet?

R Programming

result <- paste("apple", "banana", "cherry")
print(result)

A [1] "apple banana cherry"

B [1] "apple,banana,cherry"

C [1] "apple-banana-cherry"

D [1] "applebananacherry"

💡 Hint

Remember that paste uses a space as the default separator.

The paste function joins strings with a space by default, so the output is a single string with spaces between words.

❓ Predict Output

intermediate

Output of paste0 with multiple strings

What does this R code print?

R Programming

result <- paste0("red", "green", "blue")
print(result)

A [1] "redgreenblue"

B [1] "red,green,blue"

C [1] "red-green-blue"

D [1] "red green blue"

💡 Hint

paste0 joins strings without any separator.

paste0 concatenates strings directly without spaces or other separators.

🧠 Conceptual

advanced

Difference between paste and paste0

Which statement correctly describes the difference between paste() and paste0() in R?

A paste() joins strings with no separator; paste0() joins strings with a space by default.

B paste() and paste0() both join strings with a comma separator by default.

C paste() joins strings with a space by default; paste0() joins strings with no separator.

D paste() joins strings with a dash by default; paste0() joins strings with an underscore.

💡 Hint

Think about the default separator each function uses.

paste() uses a space as the default separator, while paste0() uses no separator.

❓ Predict Output

advanced

Output of paste with custom separator

What is the output of this R code?

R Programming

result <- paste("cat", "dog", "mouse", sep = "-")
print(result)

A [1] "catdogmouse"

B [1] "cat dog mouse"

C [1] "cat,dog,mouse"

D [1] "cat-dog-mouse"

💡 Hint

Look at the sep argument value.

The sep argument sets the separator between strings; here it is a dash.

❓ Predict Output

expert

Output of paste with recycling and paste0

What is the output of this R code?

R Programming

x <- c("a", "b")
y <- c(1, 2, 3)
result <- paste0(x, y)
print(result)

A [1] "a1" "a2" "a3"

B [1] "a1" "b2" "a3"

C [1] "a1" "b2" "b3"

D [1] "a1" "b2" "c3"

💡 Hint

Remember how R recycles shorter vectors to match longer ones.

R recycles the shorter vector x to match length of y, so x becomes c("a", "b", "a"). paste0 joins element-wise.