Compare arrays in swift

Question

Trying to understand how swift compares arrays.

var myArray1 : [String] = [\"1\",\"2\",\"3\",\"4\",\"5\"]
var myArray2 : [String] = [\"1\",\"2\",\"3\",\"4\",         


        

Answer 1

If you have an array of custom objects, one has to be careful with the equality test, at least with Swift 4.1:
If the custom object is not a subclass of NSObject, the comparison uses the static func == (lhs: Nsobject, rhs: Nsobject) -> Bool, which has to be defined.
If it is a subclass of NSObject, it uses the func isEqual(_ object: Any?) -> Bool, which has to be overridden.

Please check the following code, and set breakpoints at all return statements.

class Object: Equatable {

    static func == (lhs: Object, rhs: Object) -> Bool {
        return true
    }
}

The following class inheritates Equatable from NSObject

class Nsobject: NSObject {

    static func == (lhs: Nsobject, rhs: Nsobject) -> Bool {
        return true
    }


    override func isEqual(_ object: Any?) -> Bool {
        return true
    }

}  

They can be compared with:

let nsObject1 = Nsobject()
let nsObject2 = Nsobject()
let nsObjectArray1 = [nsObject1]
let nsObjectArray2 = [nsObject2]
let _ = nsObjectArray1 == nsObjectArray2

let object1 = Object()
let object2 = Object()
let objectArray1 = [object1]
let objectArray2 = [object2]
let _ = objectArray1 == objectArray2