1. Background
I did a project earlier and developed it using swift 3.x. After the end of the project, there will be no new requirements and updates. But recently, some functions of the project need to be adjusted, and the project has been picked up again. We know that the current swift version has reached 5.x, and the corresponding syntax has also changed a lot compared with the 3.x version. The latest version of xcode does not support the swift version of swift 3.x. So there are currently two solutions:
- Upgrade the project to swift 5.x (costly)
- Development tool xcode downgrade version
The adjustment this time is very small, and the time given is not much, so the plan of upgrading after synthesis is not considered for the time being. The next step is to implement the second plan.
Search for xcode in the Appstore, only the latest version is provided, and the historical version is not provided. So first determine the version of xcode that supports swift 3.x, and then find resources
| Swift version | XCode version | Mac OS version |
|---|---|---|
| Swift3.x | Xcode8.x | macOS 10.11.5+ |
| Swift4 | Xcode9.0 or later | macOS 10.12.6+ |
| Swift4.2 | Xcode10 or later | macOS 10.13.4+ |
| Swift5.0 | Xcode 10.2 | macOS 10.14.4 |
| Swift5.1 | Xcode 11 or later | macOS Mojave 10.14.4 |
| Swift5.2 | Xcode 11.4.x or later | macOS Catalina 10.15.2 |
| Swift5.3 | Xcode 12 or later | macOS Catalina 10.15.4 (Intel-based Mac) |
| Swift5.4 | Xcode 12.5 or later | macOS Big Sur 11 |
| Swift5.5 | Xcode 13（13 13.1 13.2） | macOS Big Sur 11.3 |
| Swift5.6.1 | Xcode 13.3 1 | macOS 12.0 or later |
More complete version reference: https://www.dgrt.cn/a/2029377.html
2. Find the historical version of xcode
I went to consult Apple's customer service and quickly responded:
Official address given by Apple: https://developer.apple.com/cn/support/xcode
Search for the xcode version you want to download, and click Download when you find the result.