ch8_exercise.Rmd

---
title: "迴圈與流程控制 - 隨堂練習"
author: "Yao-Jen Kuo"
date: "`r Sys.Date()`"
output: 
  html_document:
    self_contained: false
---

```{r, include=FALSE}
tutorial::go_interactive()
```

## 迴圈練習

以 for 迴圈印出 1:100 的每個數字一一印出，但是跳過 6 的倍數。使用 `%%` 運算子與 `next` 來幫助你。

```{r ex="for_loop", type="sample-code"}
# Create the vector of 1:100
my_vector <- 
  
# Write your for loop here
for (i in my_vector) {
  if (i ___ 6 == 0) {
    ___
  }
  print(i)
}
```

```{r ex="for_loop", type="solution"}
# Create the vector of 1:100
my_vector <- 1:100
  
# Write your for loop here
for (i in my_vector) {
  if (i %% 6 == 0) {
    next
  }
  print(i)
}
```

```{r ex="for_loop", type="sct"}
test_object("my_vector", incorrect_msg = "Did you assign `my_vector` correctly?")
test_output_contains("for (i in my_vector) {
  if (i %% 6 == 0) {
    next
  }
  print(i)
}", incorrect_msg = "Did you write the loop statement correctly?")
```

## 迴圈練習（2）

練習使用 `break` 把一到九月印出來。

```{r ex="break_exercise", type="sample-code"}
# Print built-in vector month.name


# Write a for loop with break statement to print out the first 9 months
for (i in ___) {
  if (i == "___") {
    break
  }
  print(i)
}
```

```{r ex="break_exercise", type="solution"}
# Print built-in vector month.name
month.name

# Write a for loop with break statement to print out the first 9 months
for (i in month.name) {
  if (i == "October") {
    break
  }
  print(i)
}
```

```{r ex="break_exercise", type="sct"}
test_output_contains("month.name", incorrect_msg = "Did you correctly print out `month.name`?")
test_output_contains("for (i in month.name) {
  if (i == \"October\") {
    break
  }
  print(i)
}", incorrect_msg = "Did you write the loop with break statement correctly?")
```