Operator precedence in R Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this R code involving arithmetic and logical operators?

Consider the following R code snippet. What will be printed when it runs?

R Programming

result <- 3 + 4 * 2 > 10
print(result)

A [1] FALSE

B [1] 11

C [1] TRUE

D [1] 14

💡 Hint

Remember that multiplication happens before addition, and comparison operators are evaluated last.

Multiplication (*) has higher precedence than addition (+), so 4 * 2 = 8. Then 3 + 8 = 11. Comparisons have lower precedence than arithmetic operators, so finally 11 > 10 is TRUE. Output: [1] TRUE.

❓ Predict Output

intermediate

What is the value of x after this R expression?

What is the value of x after running this code?

R Programming

x <- 5
x <- x ^ 2 %% 3
print(x)

A [1] 1

B [1] 4

C [1] 7

D [1] 2

💡 Hint

Remember that exponentiation (^) has higher precedence than modulo (%%).

First, x ^ 2 is 5 squared = 25. Then 25 %% 3 is the remainder of 25 divided by 3, which is 1.

❓ Predict Output

advanced

What does this R code print with mixed logical and arithmetic operators?

What is the output of this R code?

R Programming

a <- 2
b <- 3
result <- a + b > 4 & b < 5
print(result)

A [1] 5

B [1] FALSE

C [1] NA

D [1] TRUE

💡 Hint

Check operator precedence: arithmetic first, then comparison, then logical AND (&).

First, a + b = 5. Then 5 > 4 is TRUE. Also, b < 5 is TRUE. TRUE & TRUE is TRUE.

❓ Predict Output

advanced

What is the output of this R code with nested parentheses and operators?

What will this code print?

R Programming

x <- 4
result <- (x + 2) * (x - 1) / 2
print(result)

A [1] 6

B [1] 9

C [1] 8

D [1] 10

💡 Hint

Calculate inside parentheses first, then multiplication and division from left to right.

(4 + 2) = 6, (4 - 1) = 3, then 6 * 3 / 2. Since * and / have the same precedence and are left-associative, (6 * 3) / 2 = 18 / 2 = 9.

❓ Predict Output

expert

What is the output of this complex R expression with mixed operators?

What does this R code print?

R Programming

x <- 3
y <- 4
z <- 5
result <- x + y * z ^ 2 %% 7 - 1
print(result)

A [1] 4

B [1] 10

C [1] 14

D [1] 12

💡 Hint

Remember the order: exponentiation (^), modulo (%%), multiplication (*), addition (+), subtraction (-).

Precedence: ^ first (right-associative), so z ^ 2 = 25.

Then * and %% have the same precedence (left-associative), so (y * 25) %% 7 = 100 %% 7 = 2 (since 7*14=98, 100-98=2).

Then + and - (left-associative): x + 2 = 5, 5 - 1 = 4.