swift循环后如何获取所有数据数组？

Question

我创建结构来添加数据，这是我的结构：

struct data {
    var documentCode: String?
    var attachmentSize: String?
    var applicationType: String?
    var fileExtension: String?
    var file64: String
    var contentType: String
}

然后我将一些字符串添加到结构中：

let allData = [
        data(documentCode: "1", attachmentSize: "2", applicationType: "3", fileExtension: "4", file64: "5", contentType: "6"),
        data(documentCode: "a", attachmentSize: "b", applicationType: "c", fileExtension: "d", file64: "e", contentType: "f"),
        data(documentCode: "12", attachmentSize: "2", applicationType: "3", fileExtension: "4", file64: "5", contentType: "6")
    
    ]

这是我的循环，我 var datas = [String: String]() 将数据添加到字典：

 override func viewWillAppear(_ animated: Bool) {
    var datas = [String: String]()

    let allData = [
        data(documentCode: "1", attachmentSize: "2", applicationType: "3", fileExtension: "4", file64: "5", contentType: "6"),
        data(documentCode: "a", attachmentSize: "b", applicationType: "c", fileExtension: "d", file64: "e", contentType: "f"),
        data(documentCode: "12", attachmentSize: "2", applicationType: "3", fileExtension: "4", file64: "5", contentType: "6")
    
    ]
    
    for checkData in allData{

        datas = ["documentCode": checkData.documentCode, "applicationType": checkData.applicationType, "attachmentSize": checkData.attachmentSize, "fileExtension": checkData.fileExtension, "file64": checkData.file64, "contentType": checkData.contentType] as! [String : String]

        print(datas)
    }
    
    print(datas)
}

当我在循环中打印数据时，我得到这样的数据：

   ["file64": "5", "applicationType": "3", "attachmentSize": "2", "fileExtension": "4", "contentType": "6", "documentCode": "1"]
   ["file64": "e", "fileExtension": "d", "documentCode": "a", "attachmentSize": "b", "contentType": "f", "applicationType": "c"]
   ["documentCode": "12", "fileExtension": "4", "attachmentSize": "2", "applicationType": "3", "file64": "5", "contentType": "6"]

但是当我在外部循环打印时，我只得到最后一个索引数组：

   ["file64": "5", "applicationType": "3", "attachmentSize": "2", "fileExtension": "4", "contentType": "6", "documentCode": "1"]

如何在循环外获取 allData 数组？

Answer 1

老实说，你似乎想要 allData 所以 print(allData).

为了解释您的示例，设置为 datas 的最后一项将是数组中的最后一个索引 ["file64": "5", "applicationType": "3", "attachmentSize": "2", "fileExtension": "4", "contentType": "6", "documentCode": "1"]。

如果 datas 是一个位于循环内部的变量，print(datas) 的打印语句甚至不会工作。

我相信你只是想要print(allData)。

Answer 2

在循环中，您使用相同的键更新了字典，结果字典中只有一个数据。要保存您需要使用字典数组的所有数据。你可以像这样声明数据：

var datas : [[String: String]] = []

然后你可以在数组循环中追加：

for checkData in allData{

    let data = ["documentCode": checkData.documentCode, "applicationType": checkData.applicationType, "attachmentSize": checkData.attachmentSize, "fileExtension": checkData.fileExtension, "file64": checkData.file64, "contentType": checkData.contentType] as! [String : String]
    datas.append(data)
    
}
print(datas)

Answer 3

您刚刚创建了词典。你需要什么来创建“字典数组”。更新代码：-

 override func viewWillAppear(_ animated: Bool) {
    var datas = [[String: String]]()

    let allData = [
        data(documentCode: "1", attachmentSize: "2", applicationType: "3", fileExtension: "4", file64: "5", contentType: "6"),
        data(documentCode: "a", attachmentSize: "b", applicationType: "c", fileExtension: "d", file64: "e", contentType: "f"),
        data(documentCode: "12", attachmentSize: "2", applicationType: "3", fileExtension: "4", file64: "5", contentType: "6")
    
    ]
    
    for checkData in allData{
        datas.append(["documentCode": checkData.documentCode, "applicationType": checkData.applicationType, "attachmentSize": checkData.attachmentSize, "fileExtension": checkData.fileExtension, "file64": checkData.file64, "contentType": checkData.contentType] as! [String : String])

    }
    
    print(datas)

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