1. What is a user-defined function in R?
Answer:
Explanation:
A user-defined function in R refers to a function that is created by the user to perform specific tasks or calculations, as opposed to built-in functions that are provided by R.
2. Which keyword is used to define a function in R?
Answer:
Explanation:
In R, the keyword 'function' is used to define a new function.
3. How do you call a function named "myFunction" in R?
Answer:
Explanation:
Functions in R are called using their name followed by parentheses. Arguments, if any, are placed inside the parentheses.
4. Which of these is a correct way to define a function in R that takes no arguments?
Answer:
Explanation:
Functions in R are defined using the 'function' keyword, followed by parentheses. In this case, no arguments are specified inside the parentheses.
5. How can you return a value from a function in R?
Answer:
Explanation:
The return() function is used in R to return a value from a function.
6. What is the scope of a variable defined inside a function in R?
Answer:
Explanation:
Variables defined inside a function in R have local scope, meaning they are only accessible within the function.
7. What does the ellipsis (…) argument in a function definition signify in R?
Answer:
Explanation:
The ellipsis (…) is used in a function definition to indicate that the function can accept a variable number of arguments.
8. How are default values assigned to arguments in R functions?
Answer:
Explanation:
In R, default values for function arguments are assigned using the '=' operator within the function definition.
9. What is the result of using the next statement inside a loop within a function in R?
Answer:
Explanation:
The next statement in a loop within a function causes the loop to skip the rest of the current iteration and proceed to the next iteration.
10. How do you make a function parameter optional in R?
Answer:
Explanation:
In R, a function parameter is made optional by providing a default value in the function definition.
11. What does the debug() function do when applied to a function in R?
Answer:
Explanation:
The debug() function in R is used for debugging, allowing the user to step through the execution of the function one line at a time.
12. What is the purpose of the stopifnot() function in R?
Answer:
Explanation:
The stopifnot() function in R is used to assert that specified conditions are true; if any condition is false, an error is generated.
13. How can you source an external R script inside a function?
Answer:
Explanation:
The source() function in R is used to run all the commands contained in an external R script file.
14. What is the difference between library() and require() functions in R when loading a package?
Answer:
Explanation:
The library() function throws an error if the package is not available, whereas require() returns FALSE and gives a warning.
15. How do you document a function in R?
Answer:
Explanation:
In R, functions are often documented using Roxygen comments, which are special comments that can be used to generate documentation.