Class static member variables, why do you use an error-CodePudding

 import Foundation 

Print (" Hello, World!" ) 

Public class wechat: NSObject {
The static var staticSelf: wechat? 
Var a: Int=1; 

Override init () {
Super. The init () 
Wechat. StaticSelf=self 
} 
Public func loginSucc () - & gt; Void {
//the error 
Print (wechat. StaticSelf. A); 

//ok 
If let the controller=wechat. StaticSelf {
Print (controller. A); 
} 
Return 
} 
}

Why the error that part of the compiler error, here ok

CodePudding user response:

//
//main. Swift 
//testCMD 
//
//Created by LXLX - cx on 2020/1/14. 
//Copyright? 2020 LXLX - cx. All rights reserved. 
//

The import Foundation 

Print (" Hello, World!" ) 

Public class wechat: NSObject {
The static var staticSelf: wechat {
Set (selfInstance) {
Wechat. StaticSelf=selfInstance 
} 
The get {
Return wechat. StaticSelf 
} 
} 
Var a: Int=1; 

Override init () {
Super. The init () 
Wechat. StaticSelf=self 
} 
Public func loginSucc () - & gt; Void {
//the error 
Print (wechat. StaticSelf. A); 

//ok 
/* 
If let the controller=wechat. StaticSelf {
Print (controller. A); 
} 
*/
Return 
} 
}

This modified to remove the optional type can also be compiled,