Swift 字符串 為空判斷 并返回字符串
func emptyString(_ str :AnyObject)-> String
{
var string = str
var isNO:Bool!
isNO = false
if ((string as AnyObject).isEqual(String.init()))
{
isNO = true
}
else if ((string as AnyObject).isEqual(NSNull.init()))
{
isNO = true
}
else if (string as! String == "\("")")
{
isNO = true
}
else if (string as! String == "\("null")")
{
isNO = true
}
else if (string as! String == "\("(null)")")
{
isNO = true
}
else if (string as! String == "\("<null>")")
{
isNO = true
}
else if (string.isEmpty)
{
isNO = true
}
else if (string.length == 0)
{
isNO = true
}
else
{
isNO = false
}
if (isNO == true) {
string = "" as AnyObject as AnyObject
}
return string as! String
}