Randomly take wrong answers of a quiz question from dataframe column, instead of doing by hand-CodePudding

I try to make a kind of learning tool using learnr package. We have one question and for answers where one is the correct one:

Instead of putting in eachtime a wrong answer by hand I would like to take the WRONG answers randomly from the dataframe:

df1 <- tibble(letters = LETTERS, Number = 1:26)

How can I make to take randomly cell values from column Number for answer 1, 2, and 4. The correct answer is answer Nr.3.

In the first step I have tried to use deparse(substitute(df1[1,2])) instead of 1, but failed.

---
title: "Tutorial"
output: learnr::tutorial
runtime: shiny_prerendered
---

```{r setup, include=FALSE}
library(learnr)
library(tidyverse)
knitr::opts_chunk$set(echo = FALSE)
df1 <- tibble(letters = LETTERS, Number = 1:26)
```


Question 1:

```{r quiz}
# This works not
quiz(
  question("Which number has E?",
    answer(deparse(substitute(df1[1,2]))),
    answer(deparse(substitute(df1[4,2]))),
    answer(deparse(substitute(df1[5,2])), correct = TRUE),
    answer(deparse(substitute(df1[8,2])))
  ),
  # This one works
  question("Which number has E?",
    answer("1"),
    answer("4"),
    answer("5", correct = TRUE),
    answer("8")
  )
)
```

output:

CodePudding user response：

We need to convert to character class

---
title: "Tutorial"
output: learnr::tutorial
runtime: shiny_prerendered
---

```{r setup, include=FALSE}
library(learnr)
library(dplyr)    
knitr::opts_chunk$set(echo = FALSE)
df1 <- tibble(letters = LETTERS, Number = 1:26)
```


Question 1:

```{r quiz}
# This works not
quiz(
 question("Which number has E?",
       answer(as.character(df1[[2]][1])),
       answer(as.character(df1[4,2])),
       answer(as.character(df1[5,2]), correct = TRUE),
       answer(as.character(df1[8,2]))         
  ),
  # This one works
  question("Which number has E?",
       answer("1"),
       answer("4"),
       answer("5", correct = TRUE),
       answer("8")
  )
 )
 ```

-output