如何将Swift数组转换为字符串？

Question

如何将Swift数组转换为字符串？

iosarraysswift

445

我知道如何以编程方式实现它，但我相信有一种内置的方法...

我使用过的每种语言都有一些默认的文本表示方式，用于在尝试将数组与字符串连接或将其传递给print()函数等时输出。苹果的Swift语言是否具有将数组轻松转换为字符串的内置方法，还是我们总是需要明确将数组转换为字符串？

- Troy

7

Swift 4：array.description或者如果您想要自定义分隔符则使用 array.joined(separator: ",")。 - Jonathan Solorzano

25个回答

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- john07 · Answer 1

适用于任何元素类型

extension Array {

    func joined(glue:()->Element)->[Element]{
        var result:[Element] = [];
        result.reserveCapacity(count * 2);
        let last = count - 1;
        for (ix,item) in enumerated() {
            result.append(item);
            guard ix < last else{ continue }
            result.append(glue());
        }
        return result;
    }
}

- elhoucine ayoub · Answer 2

当您想将结构体类型的列表转换为字符串时，请使用此功能

struct MyStruct {
  var name : String
  var content : String
}

let myStructList = [MyStruct(name: "name1" , content: "content1") , MyStruct(name: "name2" , content: "content2")]

并将您的数组转换为以下方式

let myString = myStructList.map({$0.name}).joined(separator: ",")

将会产生 ===> "name1，name2"

- Tej Patel · Answer 3

试一下这个：

let categories = dictData?.value(forKeyPath: "listing_subcategories_id") as! NSMutableArray
                        let tempArray = NSMutableArray()
                        for dc in categories
                        {
                            let dictD = dc as? NSMutableDictionary
                            tempArray.add(dictD?.object(forKey: "subcategories_name") as! String)
                        }
                        let joinedString = tempArray.componentsJoined(by: ",")

- dheeru · Answer 4

如果你的问题是这样的： tobeFormattedString = ["a", "b", "c"] 输出结果为："abc"

那么你可以使用以下代码： String(tobeFormattedString)

- Ty Daniels · Answer 5

对于Swift 3：

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    if textField == phoneField
    {
        let newString = NSString(string: textField.text!).replacingCharacters(in: range, with: string)
        let components = newString.components(separatedBy: NSCharacterSet.decimalDigits.inverted)

        let decimalString = NSString(string: components.joined(separator: ""))
        let length = decimalString.length
        let hasLeadingOne = length > 0 && decimalString.character(at: 0) == (1 as unichar)

        if length == 0 || (length > 10 && !hasLeadingOne) || length > 11
        {
            let newLength = NSString(string: textField.text!).length + (string as NSString).length - range.length as Int

            return (newLength > 10) ? false : true
        }
        var index = 0 as Int
        let formattedString = NSMutableString()

        if hasLeadingOne
        {
            formattedString.append("1 ")
            index += 1
        }
        if (length - index) > 3
        {
            let areaCode = decimalString.substring(with: NSMakeRange(index, 3))
            formattedString.appendFormat("(%@)", areaCode)
            index += 3
        }
        if length - index > 3
        {
            let prefix = decimalString.substring(with: NSMakeRange(index, 3))
            formattedString.appendFormat("%@-", prefix)
            index += 3
        }

        let remainder = decimalString.substring(from: index)
        formattedString.append(remainder)
        textField.text = formattedString as String
        return false
    }
    else
    {
        return true
    }
}