我正在学习 Swift 教程:https://www.raywenderlich.com/125311/make-game-like-candy-crush-spritekit-swift-part-1并遇到了这段代码:
func == (lhs: Cookie, rhs: Cookie) -> Bool {
return lhs.column == rhs.column && lhs.row == rhs.row
}
我正是这么写的,但是 Xcode 给我这些错误:
Consecutive declarations on a line must be separated by ';'
Expected declaration operators are only allowed at global scope
我从苹果文档中找到这段代码:https://developer.apple.com/documentation/swift/equatable
这和我写的非常相似。怎么了?这对我来说似乎是一个错误。我正在使用 Xcode 6 Beta 2
编辑:
这是我的整个 Cookie 类:
class Cookie: Printable, Hashable {
var column: Int
var row: Int
let cookieType: CookieType
let sprite: SKSpriteNode?
init(column: Int, row: Int, cookieType: CookieType) {
self.column = column
self.row = row
self.cookieType = cookieType
}
var description: String {
return "type:\(cookieType) square:(\(column),\(row))"
}
var hashValue: Int {
return row * 10 + column
}
func ==(lhs: Cookie, rhs: Cookie) -> Bool {
return lhs.column == rhs.column && lhs.row == rhs.row
}
}
最佳答案
移动这个函数
func == (lhs: Cookie, rhs: Cookie) -> Bool {
return lhs.column == rhs.column && lhs.row == rhs.row
}
在 cookie 类之外。这种方式很有意义,因为当它用于两个 Cookie 时,它会在全局范围内覆盖 == 运算符。
关于ios - Swift 平等协议(protocol),我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24467960/