Switch statement in R Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple switch statement

What is the output of this R code using switch?

R Programming

result <- switch("b", a = 1, b = 2, c = 3)
print(result)

A NULL

B [1] 2

C [1] 3

D [1] 1

💡 Hint

Remember that switch matches the first argument to the names.

The switch matches the string "b" to the named argument b = 2, so it returns 2.

❓ Predict Output

intermediate

Switch with numeric index

What will this R code print?

R Programming

result <- switch(3, "apple", "banana", "cherry", "date")
print(result)

A [1] "cherry"

B [1] "banana"

C [1] "apple"

D [1] "date"

💡 Hint

When the first argument is a number, switch returns the element at that position.

The number 3 selects the third element, which is "cherry".

🔧 Debug

advanced

Error in switch with unnamed arguments

What error does this R code produce?

R Programming

result <- switch("x", "apple", "banana", "cherry")
print(result)

A [1] "apple"

B Error in switch: EXPR must be a length 1 vector

C NULL

D Error: no matching case found

💡 Hint

If the first argument is a string but no matching name exists, what does switch return?

When the first argument is a string and no matching name is found, switch returns NULL without error.

❓ Predict Output

advanced

Switch with expression and default

What is the output of this R code?

R Programming

x <- "z"
result <- switch(x, a = 10, b = 20, c = 30, 40)
print(result)

A [1] 40

B [1] 20

C [1] 30

D [1] 10

💡 Hint

If no named match is found, switch returns the last unnamed argument as default.

Since "z" does not match a, b, or c, switch returns the last unnamed argument 40.

🧠 Conceptual

expert

Behavior of switch with numeric zero

What happens when you run this R code?

R Programming

result <- switch(0, "apple", "banana", "cherry")
print(result)

A [1] "banana"

B [1] "apple"

C [1] "cherry"

D NULL

💡 Hint

Check how switch treats numeric indices outside the valid range.

Numeric indices less than 1 or greater than the number of options cause switch to return NULL.