ios - 如何在 swift 中使用 NSNumber 和 Int 进行 for in 循环

Question

我是 swift 新手，我无法获取数组的值，我的数组是这样的

(
    "http://ivs.upetch.com/tpaf/storage/uploads/banner/15762295031269.jpg",
    "http://ivs.upetch.com/tpaf/storage/uploads/banner/15762294973128.jpg",
    "http://ivs.upetch.com/tpaf/storage/uploads/banner/15762294928909.jpg"
)

我的代码是这样的

    self.bannerarr = bannerdata as! NSArray
    print(self.bannerarr)

    for bannerurl in self.bannerarr{
    let stringbanner = self.bannerarr .object(at: bannerurl as! Int)
    print(stringbanner)
}

但是当我尝试从数组中获取值时，它显示错误为

Could not cast value of type '__NSCFString' (0x1084207a0) to 'NSNumber' (0x10493ed40).

有人可以告诉我我做错了什么吗

Answer 1

如果您想要每个元素的索引及其值，可以使用 enumerated()迭代数组的方法。

It returns a sequence of pairs (index, element), where index represents a consecutive integer starting at zero and element represents an element of the sequence.

  let bannerarr = ["http://ivs.upetch.com/tpaf/storage/uploads/banner/15762295031269.jpg",
    "http://ivs.upetch.com/tpaf/storage/uploads/banner/15762294973128.jpg",
    "http://ivs.upetch.com/tpaf/storage/uploads/banner/15762294928909.jpg"]

    // use your iteration as like
    for (index, element) in bannerarr.enumerated() {
      print("get Index \(index): getString \(element)")

    }