We all know that in Swift, optional chaining is an important feature that can help us write concise and elegant code.

However, the optional assignment derived from the optional chain may have some strange phenomena when used.

I helped a colleague troubleshoot an issue last week. The culprit is a static variable in a header file.

A month ago, after I submitted the AppStore review as usual. Soon I received a review response with the subject line “We noticed an issue with your submission.”

I guess I may have screwed up again.

The reason for rejection is about UIRequiredDeviceCapabilities.

在公司的时候，通常 Crash 平台都做的很好，帮我们做好了符号化解析，一些三方平台也会提供类似的能力。

但我们还是会遇到需要自己做符号化解析的场景，比如某些线下包没有解析成功，又比如离开了公司提供的环境的时候等等。

所以我们还是有必要了解如何做符号化解析。

对iOS签名、证书相关知识的学习总结

本文针对 Swift 中 defer、inout 以及 return 时相互影响的时候的情况进行简单的分析，目的是更好的理解 defer、inout 原理以及使用场合，减少踩坑和提高debug效率。

本文中的示例代码，均为 Swift 4.2 版本