Return values in R Programming - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a return value in R functions?

A return value is the result that a function sends back after it finishes running. It is what you get when you call the function.

beginner

How do you explicitly return a value from a function in R?

You use the return() function inside your function to send back a specific value.

beginner

What happens if you do not use return() in an R function?

R automatically returns the last evaluated expression in the function, even if you don't use return().

intermediate

Can a function in R return multiple values?

Yes, by returning a list or other data structure, a function can return multiple values at once.

beginner

What is the difference between print() and returning a value in R?

print() shows output on the screen but does not send a value back from the function. Returning a value allows other code to use that result.

What does the return() function do in R?

A Sends a value back from a function

B Prints a value to the console

C Stops the entire program

D Creates a new variable

return() sends a value back from a function to where it was called.

If a function in R does not have a return() statement, what happens?

A The function returns the last evaluated expression

B The function returns NULL

C The function causes an error

D The function returns TRUE

R automatically returns the last evaluated expression if return() is not used.

How can a function return multiple values in R?

A By using global variables

B By using multiple <code>return()</code> statements

C By printing all values

D By returning a list containing all values

Returning a list lets a function send back multiple values together.

Which of these is NOT true about return values in R?

A Return values can be used in other parts of the program

B Return values are always printed automatically

C Return values come from functions

D Return values can be any type of data

Return values are not printed automatically; you must print them if you want to see them.

What is the main difference between print() and returning a value?

A <code>print()</code> sends a value back, return shows output

B They do the same thing

C <code>print()</code> shows output, return sends a value back

D Neither can be used in functions

print() displays output on screen; returning sends a value back for further use.

Explain what a return value is in R and how it is used in functions.

Think about what happens after a function finishes running.

Describe how you can return multiple values from a single R function.

Consider how to package several things together.