【Swift 60秒】45 - Running throwing functions

0x00 Lesson

Swift ​​doesn't​​ like errors to happen when your program runs, which means it won’t let you run an error-throwing function by accident.

Instead, you need to call these functions using three new keywords: ​​do​​​ starts a section of code that might cause problems, ​​try​​​ is used before every function that might throw an error, and ​​catch​​ lets you handle errors gracefully.

If any errors are thrown inside the ​​do​​​ block, execution immediately jumps to the ​​catch​​​ block. Let’s try calling ​​checkPassword()​​ with a parameter that throws an error:

do {
  try checkPassword("password")
  print("That password is good!")
} catch {
  print("You can't use that password.")
}

When that code runs, ​​"You can't use that password"​​​ is printed, but “That password is good” won’t be - that code will never be reached. because the ​​error​​ is thrown.

---

0x01 我的小作品

欢迎体验我的作品之一：​​小五笔​​​ 五笔学习好帮手
​​App Store​​ 搜索即可~

---