swift 赋值判断

.

 var name:String? = "Wing"
 var geting = "Hello!"
 if let thisname = name{
     geting = "Hello,\(name)"            //Hello,Wing
 }
 else
 {
     geting = "Hello,无名氏"
 }

哎！为什么if判断里是一个赋值？那能有判断吗？哦！原来是判断赋值能否成功，成功则进入if判断体里，flase则进入else。

如果将name = "Wing"改为name = nil则进入else