Question

我有一个输出以下内容的数组：

[L,W,L,W,L,L,W,W]

这是正确的值，但我希望它反转，所以它读取

[W,W,L,L,W,L,W,L]

这是我的代码：

for value in forms {

    if let arr = [value] as? [[String:Any]] {

        self.leagueForm = arr.flatMap { Form($0) }

        for form in self.leagueForm {
            self.formGuide.append(form.player_result!)
            self.formGuide = self.formGuide.reversed()

        }                       
    }
}
print ("update" ,self.formGuide)

如果没有第self.formGuide = self.formGuide.reversed()行，则它具有正确的值但顺序错误，使用此行将输出完全更改为：

[W,L,W,W,L,L,L,W]

这完全不正确???

更新：按要求提供信息：

[KeepScore.ShowCommunityViewController.Form(player_result: Optional("L"), player_name: Optional("Dicky"), result_date: Optional("2017-02-23"), result_id: Optional("93"))]
[KeepScore.ShowCommunityViewController.Form(player_result: Optional("W"), player_name: Optional("Dicky"), result_date: Optional("2017-02-23"), result_id: Optional("90"))]
[KeepScore.ShowCommunityViewController.Form(player_result: Optional("L"), player_name: Optional("Dicky"), result_date: Optional("2017-02-23"), result_id: Optional("89"))]
[KeepScore.ShowCommunityViewController.Form(player_result: Optional("W"), player_name: Optional("Dicky"), result_date: Optional("2017-02-23"), result_id: Optional("88"))]
[KeepScore.ShowCommunityViewController.Form(player_result: Optional("L"), player_name: Optional("Dicky"), result_date: Optional("2017-02-22"), result_id: Optional("57"))]
[KeepScore.ShowCommunityViewController.Form(player_result: Optional("L"), player_name: Optional("Dicky"), result_date: Optional("2017-02-22"), result_id: Optional("56"))]
[KeepScore.ShowCommunityViewController.Form(player_result: Optional("W"), player_name: Optional("Dicky"), result_date: Optional("2017-02-22"), result_id: Optional("55"))]
[KeepScore.ShowCommunityViewController.Form(player_result: Optional("W"), player_name: Optional("Dicky"), result_date: Optional("2017-02-22"), result_id: Optional("54"))]`

更新的代码：

if let forms = json?["playerForm"] as? [[String: Any]] {

    print (forms)

    for value in forms {

        if let arr = [value] as? [[String:Any]] {

            self.leagueForm = arr.flatMap { Form($0) }
            self.formGuide = self.leagueForm.flatMap { $0.player_result }.reversed()

        }
    }
    print ("update" ,self.formGuide)

Answer 1

我认为你需要

self.formGuide = forms.reversed()

Answer 2

问题是你在for循环中使数组反转，你在数组中添加对象，这是你遇到这个问题的原因。

要解决这个问题，只需在reversedArray = reversedArray.reversed()之后放置行for loop或避免使用for loop并使用flatMap，就像用来创建字典数组中的对象数组一样

self.formGuide = self.leagueForm.flatMap { $0.player_result }.reversed()

修改：您正在if if中添加for loop，并且没有必要。

if let forms = json?["playerForm"] as? [[String: Any]] {

    self.leagueForm = forms.flatMap { Form($0) }
    self.formGuide = self.leagueForm.flatMap { $0.player_result }.reversed()
}

Answer 3

您只需致电

即可

self.formGuide.reverse()

您希望以相反的顺序访问数组，例如在您的进一步代码执行中或存储它。只是不要在你向数组中添加东西的循环中调用它。

Answer 4

您可以保留第一个代码示例，然后将self.formGuide = self.formGuide.reversed()放在for loop

之后

for value in forms {
    if let arr = [value] as? [[String:Any]] {
        self.leagueForm = arr.flatMap { Form($0) }

        for form in self.leagueForm {
            self.formGuide.append(form.player_result!)
        }
    }
}

self.formGuide = self.formGuide.reversed()
print ("update" ,self.formGuide)

为什么这个数组没有以正确的顺序反转？

4 个答案: