Variable assignment (<- and =) in R Programming - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the <- operator do in R?

The <- operator assigns a value to a variable in R. It stores the value on the right into the variable on the left.

beginner

How is the = operator used in R for variable assignment?

The = operator can also assign values to variables in R, similar to <-, but <- is preferred for clarity in scripts.

beginner

Which operator is preferred for assignment in R scripts: <- or =?

The <- operator is preferred for assignment in R scripts because it clearly shows assignment and avoids confusion with function arguments.

intermediate

Can you use both <- and = interchangeably for assignment in R?

Yes, both <- and = can assign values to variables, but <- is recommended for assignments and = is often used for function arguments.

beginner

What happens if you write x <- 5 and then x = 10 in R?

The variable x first gets the value 5, then it is updated to 10. Both assignments change the value stored in x.

Which operator is traditionally used for variable assignment in R?

A ->

B =

C ==

D <-

The <- operator is the traditional and preferred way to assign values to variables in R.

What does the = operator do in R when used outside function calls?

A Assigns a value to a variable

B Checks equality

C Creates a function

D Comments out code

Outside function calls, = assigns values to variables, similar to <-.

Which of these is NOT a correct way to assign 10 to variable x in R?

A 10 -> x

B x = 10

C x == 10

D x <- 10

x == 10 checks if x equals 10; it does not assign a value.

If you write x <- 5 and then x = 7, what is the value of x?

A 7

B 5

C 12

D Error

The second assignment updates x to 7.

Why is <- preferred over = for assignment in R scripts?

A Because = is only for comparisons

B Because <- is clearer and avoids confusion with function arguments

C Because = causes errors

D Because <- is faster

Using <- makes it clear you are assigning a value, not passing an argument.

Explain how to assign values to variables in R using both <- and = operators.

Think about how you store a value in a box labeled with a name.

Describe why <- is preferred over = for variable assignment in R scripts.

Consider how to make your code easier to read and understand.