I'm going to jump over to this Objective-C file, and this bit of code that I just added, it has a small problem.

我要跳转到这个 Objective-C 文件上，而我刚加入的这几行代码有一点小问题。

We used objective C and our professors had no clue about it.

我们使用了目标 C，而我们的教授对此一无所知。

Now, this particular issue is new in Objective-C, and it's warning me that I'm using iOS 11 API, but my project here, it deploys back to iOS X, where this would crash.

这个事件在 Objective-C 中是全新的，而且它还警告我，我正在使用 iOS 11的 API，但我的程序的配置却是 iOS 10 的，这会导致系统崩溃。