swift - 在对象中 append 时避免值相乘

Question

我想问一下如何解决我的问题。我只是简单地将一些“门户” append 到依赖的国家/地区。每个“门户”出现不止一次，我不想 append 。

我有以下类定义:

class cls_main{
    var countries:[cls_country]!

    init() {
        countries = [cls_country]()
    }

    // "add Country"
    func addCountry(iCountry:cls_country) {
        countries.append(iCountry)
    }

}

class cls_country{

    var countryName:String!
    var portals:[cls_portal]!

    init() {
        portals = [cls_portal]()
    }

    // "add Portal"
    func addPortal(portName:String) {

        var tmpPortal = cls_portal()
        tmpPortal.portalName = portName

        println("-->Input Portal: \(tmpPortal.portalName)")

        if portals.count == 0 {
            portals.append(tmpPortal)
        } else {
            for port in portals {
                if port.portalName == portName {            
                    println("SAME INPUT, DONT SAVE")  
                } else {
                    portals.append(tmpPortal)
                }
            }
        }

    }

    func arrayCount(){
        println("Portals   : \(portals.count)")
    }
}

class cls_portal{
    var portalName:String!
}

所以我将其称为:

var MAIN = cls_main()
var country = cls_country()

country.countryName = "USA"
country.addPortal("Dance")
country.addPortal("Dance") // Should not be appended...
country.addPortal("Hike")
country.addPortal("Swim")
country.addPortal("Play")

MAIN.addCountry(country)
country = cls_country()

添加值后，我循环遍历这些值并打印它们。结果会是这样的:

循环:

for country in MAIN.countries {
      println("COUNTRY: \(country.countryName)")

      if country.countryName == "USA" {
        for portal in country.portals {
            println(" -> PORTAL   : \(portal.portalName)")
        }
        country.arrayCount()    
      }
} 

结果:

-->Input Portal: Dance
-->Input Portal: Dance
SAME INPUT, DONT SAVE
-->Input Portal: Hike
-->Input Portal: Swim
-->Input Portal: Play
COUNTRY: USA
 -> PORTAL   : Dance
 -> PORTAL   : Hike
 -> PORTAL   : Swim
 -> PORTAL   : Swim
 -> PORTAL   : Play
 -> PORTAL   : Play
 -> PORTAL   : Play
 -> PORTAL   : Play
Portals   : 8

那么为什么每个传送门最终都会成倍增加？非常感谢。

Answer 1

在搜索循环中，您在查看每个元素后决定 tmpPortal 是否在您的 portals 中。在做出决定之前，您可能需要查看所有项目。添加变量 found 以表明已找到它。找到该项目后，您可以break跳出循环。

if portals.count == 0 {
    portals.append(tmpPortal)
} else {
    var found = false
    for port in portals {
        if port.portalName == portName {
            println("SAME INPUT, DONT SAVE")
            found = true
            // found it, stop searching
            break
        }
    }
    if !found {
        portals.append(tmpPortal)
    }
}