R6 classes in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a new R6 class named 'Person'.

R Programming

Person <- R6Class([1] = "Person")

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

Aclassname

Bid

Cname

Dclass

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'class' or 'name' instead of 'classname' causes errors.

The argument to R6Class() to name the class is classname.

2fill in blank

medium

Complete the code to add a public method 'greet' that prints 'Hello!'.

R Programming

Person <- R6Class(classname = "Person",
  public = list(
    greet = function() {
      print([1])
    }
  )
)

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

A"Hello!"

B'Hi!'

CHello!

D'Hello'

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes or using single quotes without exclamation mark.

The print function requires a string in quotes. Double quotes around 'Hello!' are correct.

3fill in blank

hard

Fix the error in the code to correctly initialize a field 'name' with a default value 'John'.

R Programming

Person <- R6Class(classname = "Person",
  public = list(
    name = [1],
    initialize = function(name = "John") {
      self$name <- name
    }
  )
)

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

ANA

B"John"

CNULL

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Setting the field directly to a string causes errors before initialize runs.

Fields should be initialized as NULL or a default value. Setting to NULL avoids errors before initialization.

4fill in blank

hard

Fill both blanks to add a private field 'age' and a public method 'get_age' that returns it.

R Programming

Person <- R6Class(classname = "Person",
  private = list(
    [1] = NULL
  ),
  public = list(
    get_age = function() {
      return(private$[2])
    }
  )
)

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

Aage

Cname

Dage_value

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the private field and in the method causes errors.

The private field is named 'age', and the public method accesses it as 'private$age'.

5fill in blank

hard

Fill all three blanks to create a method 'set_name' that updates the 'name' field and prints confirmation.

R Programming

Person <- R6Class(classname = "Person",
  public = list(
    name = NULL,
    set_name = function(new_name) {
      self$[1] <- [2]
      print(paste("Name set to", [3]))
    }
  )
)

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

Aname

Bnew_name

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up variable names or forgetting 'self$' causes errors.

The method sets self$name to new_name and prints it.