Integer type in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create an integer variable with value 10.

R Programming

x <- [1]

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

A"10"

B10L

C10.0

Das.character(10)

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes makes it a string, not an integer.

Using a decimal point makes it a numeric (double), not an integer.

In R, adding L after a number makes it an integer literal.

2fill in blank

medium

Complete the code to check if variable y is of integer type.

R Programming

is.integer([1])

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

A10

B"y"

Cas.integer(y)

Dy

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the value 10 instead of the variable.

Passing the variable name as a string.

The function is.integer() checks the type of the variable passed to it.

3fill in blank

hard

Fix the error in the code to convert a numeric value to integer.

R Programming

z <- [1](5.7)

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

Aas.integer

Bas.character

Cas.numeric

Das.logical

Attempts:

3 left

💡 Hint

Common Mistakes

Using as.character() converts to string, not integer.

Using as.logical() converts to TRUE/FALSE, not integer.

Use as.integer() to convert numeric values to integers in R.

4fill in blank

hard

Fill both blanks to create a vector of integers from 1 to 5 and check its type.

R Programming

vec <- [1](1:5)
is_int <- [2](vec)

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

Aas.integer

Bis.integer

Cas.numeric

Dis.numeric

Attempts:

3 left

💡 Hint

Common Mistakes

Using as.numeric instead of as.integer.

Using is.numeric instead of is.integer.

as.integer() converts the sequence to integers, and is.integer() checks if the vector is integer type.

5fill in blank

hard

Fill all three blanks to create an integer vector, convert a number to integer, and check if it is integer.

R Programming

int_vec <- [1](c(2.5, 3.7, 4.1))
num <- [2](5.9)
check <- [3](num)

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

Aas.numeric

Bas.integer

Cis.integer

Dis.numeric

Attempts:

3 left

💡 Hint

Common Mistakes

Using as.numeric() instead of as.integer().

Using is.numeric() instead of is.integer().

Use as.integer() to convert values to integers and is.integer() to check the type.

Practice

1. What does adding L after a number in R do?

easy

A. It makes the number an integer type.

B. It converts the number to a character string.

C. It makes the number a decimal (double) type.

D. It comments out the number in the code.

Solution

1. Step 1: Understand the role of L in R

   In R, adding L after a number explicitly marks it as an integer type instead of the default double (decimal) type.

2. Step 2: Compare with other types

   Without L, numbers are treated as doubles. Adding L ensures the number is stored as an integer.

3. Final Answer:

   It makes the number an integer type. -> Option A

4. Quick Check:

   Number + L = Integer type [OK]

Hint: Remember: number + L means integer in R [OK]

Common Mistakes:

• Thinking L converts to string
• Assuming numbers are integers by default
• Confusing L with a comment

2. Which of the following is the correct way to create an integer value 10 in R?

easy

A. 10.0

B. as.integer("ten")

C. 10L

D. "10"

Solution

1. Step 1: Identify integer syntax in R

   In R, appending L to a number creates an integer literal, so 10L is an integer 10.

2. Step 2: Check other options

   10.0 is a double, "10" is a string, and as.integer("ten") will cause an error because "ten" is not numeric.

3. Final Answer:

   10L -> Option C

4. Quick Check:

   10L creates integer 10 [OK]

Hint: Use L after number for integer, not quotes or decimals [OK]

Common Mistakes:

• Using decimal like 10.0 instead of 10L
• Putting number in quotes to make integer
• Trying to convert non-numeric string to integer

3. What is the output of this R code?

x <- 5L
typeof(x)

medium

A. "double"

B. "integer"

C. "numeric"

D. "character"

Solution

1. Step 1: Understand the variable assignment

   The variable x is assigned 5L, which is an integer literal in R.

2. Step 2: Use typeof() function

   The typeof() function returns the internal type of the object. Since x is an integer, it returns "integer".

3. Final Answer:

   "integer" -> Option B

4. Quick Check:

   typeof(5L) = "integer" [OK]

Hint: typeof(5L) returns "integer" not "double" [OK]

Common Mistakes:

• Assuming 5L is double type
• Confusing typeof() with class()
• Expecting numeric instead of integer

4. Identify the error in this R code:

num <- 7
int_num <- numL

medium

A. Missing L after 7 to make integer

B. Cannot assign numeric to integer variable

C. Syntax error due to missing comma

D. Variable numL is not defined

Solution

1. Step 1: Check variable names

   The code tries to assign numL to int_num, but numL is not defined anywhere.

2. Step 2: Understand the error type

   This causes an error because R cannot find the variable numL. The correct way to make num integer is 7L, but here the error is undefined variable.

3. Final Answer:

   Variable numL is not defined -> Option D

4. Quick Check:

   Undefined variable causes error [OK]

Hint: Check variable names carefully for typos [OK]

Common Mistakes:

• Assuming numL is a valid variable
• Thinking missing L after 7 causes error here
• Ignoring undefined variable errors

5. You have a vector v <- c(1, 2, 3). How do you convert all elements to integers efficiently?

hard

A. v <- as.integer(v)

B. v <- c(1L, 2L, 3L)

C. v <- as.character(v)

D. v <- as.numeric(v)

Solution

1. Step 1: Understand the vector type

   The vector v is numeric (double) by default because numbers have no L suffix.

2. Step 2: Convert vector elements to integer

   Using as.integer(v) converts all elements to integer type efficiently without rewriting the vector manually.

3. Final Answer:

   v <- as.integer(v) -> Option A

4. Quick Check:

   Use as.integer() to convert vector elements [OK]

Hint: Use as.integer() to convert numeric vectors to integer [OK]

Common Mistakes:

• Manually rewriting vector with L suffix
• Using as.character() which converts to strings
• Using as.numeric() which keeps double type