在Swift中使用Equatable将对象比较为属性

Question

AMRoute class has two properties, city1 & city2, of type AMCity class. Numerous AMRoutes are stored in an array, arrayOfRoutes. When creating a new route, I first need to ensure no routes exist with two given cities.

I am having a hard time translating this working Obj-C code:

-(void)createRouteFromCity:(AMCity*)city1 toCity:(AMCity*)city2 {

 BOOL routeExists = NO; for (AMRoute *route in self.arrayOfRoutes) { if (((route.city1 == city1) && (route.city2 == city2)) || ((route.city2 == city1) && (route.city1 == city2))) { routeExists = YES; } } 

It is my understanding that I cannot use the '==' operator to compare objects like I used to in Obj-C. The examples I found while searching the topic point me to generics:

    func createRoute(city1: AMCity, city2: AMCity) {

    var routeExists = false

    findIndex(self.arrayOfRoutes, valueToFind: <#T#>) //i am not sure how to call this?        
    for route:AMRoute in self.arrayOfRoutes {
    println("The city is: \(route.city1.name)")

    }

}

func findIndex<T: Equatable>(array: [T], valueToFind: T) -> Int? {
    for (index, value) in enumerate(array) {
        if value == valueToFind {
            return index
        }
    }
    return nil
}

I'm not sure how to incorporate this in my case. I don't need to compare AMRoute objects in the array. I need to compare objects stored as properties of AMRoute, city1 & city2 as AMCity objects.

Answer 1

您可以使用“ ===”相同的运算符快速比较对象。