R Programming Language Certification Technology & Digital Applications 2

Question 1

Which R package is specifically designed for connecting to and querying relational databases using a unified interface?

Accepted Answer

DBI

Answer

DBI (DataBase Interface) provides a unified interface for connecting to relational databases in R, and other packages like RSQLite and RMySQL implement the DBI specification.

Question 2

In R, which function from the `httr` package sends an HTTP GET request to a web API?

Accepted Answer

GET()

Answer

The `GET()` function in the httr package sends an HTTP GET request and returns a response object containing status, headers, and content.

Question 3

What does the `jsonlite::fromJSON()` function do in R?

Accepted Answer

Parses a JSON string or file into an R object

Answer

`fromJSON()` parses JSON-formatted text or files and converts them into native R objects like lists, data frames, or vectors.

Question 4

Which R package provides tools for working with date-time data, including parsing, arithmetic, and time zone handling?

Accepted Answer

lubridate

Answer

The lubridate package simplifies working with dates and times by providing intuitive parsing functions and consistent handling of time zones and arithmetic.

Question 5

In R Shiny, what is the role of the `renderPlot()` function?

Accepted Answer

Creates a reactive plot output that updates when inputs change

Answer

`renderPlot()` is a reactive rendering function in Shiny that re-executes its code block and updates the displayed plot whenever reactive dependencies change.

R Programming Language Certification Practice Test

R Programming Language Certification Practice Test

R Programming Language Certification Technology & Digital Applications 2