將Objective-C語法轉換爲Swift 3

Question

Swift中以下Objective-C方法的語法是什麼？

-(id)init 
{ 
    Viewcontroller static *vc=nil; 
    if(!vc) 
    { 
     vc=[super init]; 
     return vc; 
    } 
    else return vc; 
} 

Answer 1

下面是斯威夫特3

override init() { 
    var vc: Viewcontroller? = nil 
    if vc == nil { 
     vc = super.init() 
     return vc! 
    } 
    else {  
     return vc! 
    } 
}